Core-shell resin particle having low content of volatile components, and resin dispersion

ABSTRACT

The present invention relates to core-shell resin particles (C2) each comprising one or more film-like shell layers (P) comprising a first resin (a) and a core layer (Q) comprising a second resin (b). The core-shell resin particle (C2) is characterized in that the weight ratio between (P) and (Q) is from 0.1:99.9 to 70:30, the volatile content in the resin particle (C2) is not more than 2 weight %, and the resin (a) has an initial softening temperature of 40 to 270° C., a Tg of 20 to 250° C., a flow temperature of 60 to 300° C., and the difference of the Tg and the flow temperature in a range of 0 to 120° C. The resin particles are excellent in electrostatic property, thermal storage stability and thermal properties, and exhibit a narrow particle diameter distribution.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of international applicationnumber PCT/JP/2005/001371, which has an international filing date of 31Jan. 2005 and a claimed priority date of 30 Jan. 30, 2004, which isincorporated herein by reference. The claimed priority date is based onJapanese Patent Application Numbers 2004-024582 (filed 30 Jan. 2004),2004-253512 (filed 31 Aug. 2004), and 2004-296862 (filed 8 Oct. 2004),which are incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a resin dispersion and resin particles. Morespecifically, the invention relates to resin particles and theirwater-based dispersion useful for various uses such as a powder coating,an electrophotographic toner, an electrostatic recording toner, and thelike.

PRIOR ART

As resin particles having even particle diameters and excellent inelectric properties, thermal properties, and chemical stability havebeen known resin particles using polymer fine particles as a dispersionstabilizer (reference to Patent Document 1)

Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No.2002-284881

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

However, in the method of using the polymer fine particles, the fineparticles sometimes remain and adhere to the resin surface to becomeinterfering substances for fixation or electrostatic charging.Therefore, for powder coatings and toners to be used forelectrophotography, electrostatic recording, and electrostatic printing,using the polymer fine particles have not necessarily sufficientlyexhibited the advantageous properties (e.g. electrostatic property,thermal resistant storage stability, low temperature fixing property) ofmain resins.

In view of the above-mentioned state of the art, the invention has beenaccomplished. That is, the aim of the invention is to provide resinparticles excellent in electrostatic property, thermal resistant storagestability, and thermal properties, and having even particle diameters.

Means for Solving the Problems

The inventors of the invention have made various investigations to solvethe above-mentioned problems and the findings from the investigationshave now led to completion of the invention.

That is, the invention includes the following ten inventions.

[1] Core-shell type resin particles (C2) each comprising a film-likeshell layer (P) in one or more layer structure comprising a first resin(a) and a core layer (Q) in one layer structure comprising a secondresin (b), wherein the weight ratio of (P) and (Q) is in a range of(0.1:99.9) to (70:30), the content of volatile components of (C2) is 2%by weight or lower, and (a) has an initial softening temperature of 40to 270° C., a glass transition temperature of 20 to 250° C., a flowtemperature of 60 to 300° C., and the difference of the glass transitiontemperature and the flow temperature in a range of 0 to 120° C.

[2] A water-based dispersion (X1) of resin particles (C1) comprisingresin particles (B) bearing resin particles (A) on the surface thereofand obtained by dispersing a second resin (b) or its solvent solution,alternatively a precursor (b0) of the resin (b) or its solvent solution,further causing a reaction of (b0) in the case of using (b0) or itssolvent solution, in a water-based dispersion (W) of resin particles (A)comprising a first resin (a); and thereby forming the resin particles(B) comprising (b) in (W), wherein a point (K,H) is within an areasurrounded by a quadrangle defined by the following four points A, B, C,and D including the side lines in a system of K, H coordinates wherein Kdenotes sp value difference (Δsp) of (a) and (b) and H denotes thenatural logarithm [ln(Mw)] of the weight average molecular weight of(a):

A (0.3, ln 3000), B (1.5, ln 1000), C (1.3, ln 200000), and D (0.1, ln200000).

[3] A water-based dispersion (X1) of resin particles (C1) comprisingresin particles (B) bearing resin particles (A) on the surface andobtained by dispersing a second resin (b) or its solvent solution,alternatively a precursor (b0) of the resin (b) or its solvent solution,further causing a reaction of (b0) in the case of using (b0) or itssolvent solution, in a water-based dispersion (W) of resin particles (A)comprising a first resin (a); and thereby forming the resin particles(B) comprising (b) in (W), wherein (a) is a resin having an initialsoftening temperature of 40 to 270° C., a glass transition temperatureof 20 to 250° C., a flow temperature of 60 to 300° C., and thedifference of the glass transition temperature and flow temperature in arange from 0 to 120° C.

[4] A water-based dispersion (X1) of resin particles (C1) comprisingresin particles (B) bearing resin particles (A) on the surface thereofand obtained by dispersing a second resin (b) or its solvent solution,alternatively a precursor (b0) of the resin (b) or its solvent solution,further causing a reaction of (b0) in the case of using (b0) or itssolvent solution, in a water-based dispersion of resin particles (A)comprising a first resin (a); and thereby forming the resin particles(B) comprising (b) in the water-based dispersion of (A), wherein (a)contains a constituent unit of the following organic acid metal salt(m), and/or (A) contains the following organic acid metal salt (m):

organic acid metal salt (m): one or more kinds of salts selected fromcarboxylic acid salts, sulfonic acid salts, and phosphoric acid salts ofa metal selected from Al, Ti, Cr, Mn, Fe, Zn, Ba, and Zr.

[5] Resin particles obtained by removing the water-based solvent fromthe water based resin dispersion (X1) of one of [2], [3], and [4].

[6] A water-based resin dispersion (X2) of resin particles (C21)obtained by forming a shell layer (P) in the form of a film made of (A)on the surface of a core layer (Q) containing (B) by dissolving (A)adhering to (B) in the solvent and/or melting (A) adhering to (B) in thewater-based resin dispersion (X1) of one of [2], [3], and [4].

[7] Resin particles obtained by removing the water-based solvent fromthe water based resin dispersion (X2) of [6].

[8] A water-based dispersion (X2) of resin particles (C21) obtained byforming a shell layer (P) in the form of a film made of resinparticle(s) (A) on the surface of a core layer (Q) composed of a resinparticle (B) by obtaining a water-based dispersion (X1) of resinparticles (C1) comprising (B) bearing (A) on the surface thereof bydispersing a second resin (b) or its solvent solution, alternatively aprecursor (b0) of the resin (b) or its solvent solution, further causinga reaction of (b0) in the case of using (b0) or its solvent solution, ina water-based dispersion of (A) comprising a first resin (a); andthereby forming (B) comprising (b) in the water-based dispersion of (A)and then dissolving (A) adhering to (B) in the solvent and/or melting(A) adhering to (B) in the water-based dispersion (X1).

[9] Resin particles obtained by removing the water-based solvent fromthe water based resin dispersion (X2) of [8].

[10] A production method of resin particles by obtaining a water-baseddispersion (X1) of resin particles (C1) comprising resin particles (B)bearing resin particles (A) on the surface thereof by dispersing asecond resin (b) or its solvent solution, alternatively a precursor (b0)of the resin (b) or its solvent solution, further causing a reaction of(b0) in the case of using (b0) or its solvent solution, in a water-baseddispersion of (A) comprising a first resin (a) and thereby forming theresin particles (B) comprising (b) in the water-based dispersion of (A);obtaining water-based dispersion (X2) of resin particles (C21) obtainedby forming a shell layer (P) in the form of a film made of resinparticle(s) (A) on the surface of a core layer (Q) composed of a resinparticle (B) by successively dissolving (A) adhering to (B) in thesolvent and/or melting (A) adhering to (B) in the water-based dispersion(X1); and finally removing the water-based solvent from the water baseddispersion (X2)

EFFECTS OF THE INVENTION

A resin dispersion of the invention and resin particles obtained fromthe dispersion have the following effects.

1. Excellent in thermal property and electrostatic property, and havingeven particle diameters.

2. Excellent in thermal resistant storage stability and powderflowability.

3. Excellent in smoothness of particle surfaces (particularly in thecase of having a shell layer in the form of a film).

4. Since resin particles can be obtained by dispersion in water,production is carried out at a low cost.

5. Good mechanical physical properties of heated and melted coating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing a correlation of the sp value difference (K)of (a) and (b) and the natural logarithm ln(Mw) (H) of the weightaverage molecular weight (Mw) of (a).

FIG. 2 is a schematic view showing a flow chart of flow testermeasurement of resin particles.

BEST MODES FOR CARRYING OUT THE INVENTIONS

With respect to core-shell type resin particles (C2) each comprising afilm-like shell layer (P) in one or more layer structure comprising afirst resin (a) and a core layer (Q) in one layer structure comprising asecond resin (b) of the first invention, the weight ratio of (P) and (Q)is preferably in a range of (0.1:99.9) to (70:30), more preferably in arange of (1:99) to (50:50), and even more preferably in a range of(1.5:98.5) to (30:70) in terms of particle diameter evenness, storagestability, and fixing property of the resin particles (C2). If theweight of the shell part is too low, the blocking resistance maypossibly be decreased. Meanwhile, if the weight of the shell part is toohigh, the fixing property, particularly low temperature fixing property,may possibly be decreased.

(P) may be formed in two or more (e.g. 2 to 5 layers) layers, however itis preferably in a single layer.

Further, content of volatile components of (C2) is generally 2% or lowerand more preferably 1% or lower. If the content of the volatilecomponents exceeds 2%, the thermal resistant storage stability maypossibly be decreased. In the inventions, the content of volatilecomponents means the decrease of the weight after heating a sample at150° C. for 45 minutes. “%” in the description above and hereinaftermeans % by weight unless otherwise specified.

In the first, eighth, and tenth inventions, any resin may be used as theresin (a) if it is suitable to form the shell layer (P). In the secondinvention, any resin can be used as (a) if it satisfied theabove-mentioned condition of the correlation between the sp valuedifference K from that of the resin (b) to be used and the naturallogarithms value H [ln(Mw)] of the weight average molecular weight of(a) and is usable for forming the water-based dispersion (W). In thethird invention, any resin can be used as (a) if it has theabove-mentioned initial softening temperature, glass transitiontemperature, flow temperature, and difference between the glasstransition temperature and the flow temperature and is usable forforming the water-based dispersion (W). In the fourth invention, anyresin can be used as (a) if it is usable for forming the water-baseddispersion.

In the fourth invention, in terms of the electrostatic property, it isindispensable that the above-mentioned organic acid metal salt (m) iscontained as the constituent unit of the resin (a) and/or theabove-mentioned organic acid metal salt (m) is contained in the resinparticles (A). If (m) is contained, resin particles excellentparticularly in electrostatic property are obtained and therefore it ispreferable. Carboxylic acids are preferable as the organic saltcomposing (m). Zn and Fe are preferable among metals and Zn is morepreferable.

Among them, it is preferable that (A) contains (m) in terms of theeasiness of the preparation.

Resins other than a polyurethane resin are contained as the resin (a)and which may be thermoplastic resins and thermosetting resins.

Examples usable as resin (a) are vinyl resins, epoxy resins, polyesterresins, polyamide resins, polyimide resins, silicon resins, phenolresins, melamine resins, urea resins, aniline resins, ionomer resins,and polycarbonate resins. The resin (a) may include two or more of theabove-mentioned resins. Preferable resins among them are polyesterresins, epoxy resins, vinyl resins, and their combinations in terms ofthe easiness of shell layer formation.

Generally in the inventions, particularly in the second invention, toobtain the water-based dispersion (W) of fine and spherical resinparticles (A) and to obtain the water-based dispersion (X1) of resinparticles (C1) excellent in the thermal resistant storage stability, andelectrostatic property and having even particle diameter, the resin (a)is preferable to have sulfonic acid anion (—SO₃ ⁻). The total content ofsulfonic acid anion (—SO₃ ⁻) is preferably 0.001 to 10% of the weight of(a). The lower limit is more preferably 0.002% and the upper limit ismore preferably 5%, further preferably 2%, and even more preferably 1%.The number of carbon atoms of a monomer having sulfonic acid anion (—SO₃⁻) and composing the resin is preferably in a range from 3 to 50, morepreferably in a range from 3 to 30, and even preferably in a range from4 to 15.

If the content of sulfonic acid anion (—SO₃ ⁻) is the above-mentionedlower limit or higher and the number of carbon atoms of the monomercontaining sulfonic acid anion (—SO₃ ⁻) and composing the resin is theabove-mentioned upper limit or lower, the resin (a) is easy to bedispersed in a water-based solvent and the water-based dispersion (W) ofthe fine and spherical resin particles (A) can easily be obtained. Also,the blocking resistance and electrostatic property of the obtained resinparticles (C1) or (C2) [(C2) includes (C21). Hereinafter, “(C1) or (C2)”may be sometime referred to as (C)] are improved.

Further, generally in the inventions, particularly in the thirdinvention, to obtain the water-based dispersion (W) of fine andspherical resin particles (A), it is preferable for the resin (a) tocontain carboxyl groups. At least some of the carboxyl groups may beneutralized with a base. The neutralization ratio of the carboxyl groupswith a base is preferably 20 to 100% by equivalent and more preferably40 to 100% by equivalent.

The content of carboxyl groups [in the case of neutralization with abase, the content based on the conversion into carboxyl (—COOH) groups]is preferably 0.1 to 10% of the weight of (a). The lower limit is morepreferably 0.5%, furthermore preferably 1%, and even more preferably 3%and the upper limit is more preferably 9.5%, furthermore preferably 9%,and even more preferably 8%.

If the neutralization with a base and the content of the carboxyl groupsare the above-mentioned lower limit or higher, the resin (a) is easy tobe dispersed in a water-based solvent and the water-based dispersion (W)of the fine and spherical resin particles (A) can easily be obtained.Also, the electrostatic property of the obtained resin particles (C) isimproved.

The above-mentioned base for forming the neutral salt may be ammonia,monoamines having 1 to 30 carbon atoms, polyamines (21) described later,quaternary ammoniums, alkali metals (e.g., sodium and potassium), andalkaline earth metals (e.g. calcium salts and magnesium salts).

The monoamines having 1 to 30 carbon atoms may include primary and/orsecondary amines having 1 to 30 carbon atoms (e.g., ethylamine,n-butylamine, and isobutylamine), tertiary amines having 3 to 30 carbonatoms (e.g., trimethylamine, triethylamine, lauryldimethylamine). Thequaternary ammoniums may include trialkylammonium having 4 to 30 carbonatoms (e.g., lauryltrimethylammonium).

Among them alkali metals, quaternary ammoniums, monoamines, andpolyamines are preferable; sodium and monoamine having 1 to 20 carbonatoms are more preferable; and tertiary monoamines having 3 to 20 carbonatoms are even more preferable.

The carbon atom number of monomers containing carboxyl or its saltcomposing the vinyl resins and polyester resins is preferably 3 to 30,more preferably 3 to 15, and even more preferably 3 to 8.

Hereinafter, vinyl resins, polyester resins, and epoxy resins preferableto be used will be described more in detail.

Vinyl resins are polymers obtained by homopolymerization orcopolymerization of vinyl monomers. The vinyl monomers may include thefollowing (1) to (10).

(1) Vinyl hydrocarbons:

(1-1) aliphatic vinyl hydrocarbons: alkenes such as ethylene, propylene,butane, isobutylene, pentene, heptene, diisobutylene, octane, dodecene,octadecene, and α-olefins other than the above-mentioned alkenes; andalkadienes such as butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene,and 1,7-octadiene:(1-2) alicyclic vinyl hydrocarbons: mono- or di-cycloalkene andalkadienes, e.g., cyclohexene, (di)cyclopentadiene, vinylcyclohexene,and ethylidenebicycloheptene; and terpenes e.g., pinene, limonene, andindene: and(1-3) aromatic vinyl hydrocarbons: styrene and its hydrocarbyl (e.g.,alkyl, cycloalkyl, aralkyl and/or alkenyl)-substituted compounds, e.g.,α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene,isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene,benzylstyrene, crotylbenzene, divinylbenzene, divinyltoluene,divinylxylene, and trivinylbenzene, and vinylnaphthalene.(2) Carboxyl group-containing vinyl monomers and their metal salts:unsaturated monocarboxylic acids having 3 to 30 carbon atoms,unsaturated dicarboxylic acids having 3 to 30 carbon atoms, theiranhydrides, and their monoalkyl (1 to 24 carbon atoms) esters, e.g.,(meth)acrylic acid, maleic acid (anhydride), maleic acid monoalkylester, fumaric acid, fumaric acid monoalkyl ester, crotonic acid,itaconic acid, itaconic acid monoalkyl ester, itaconic acid glycolmonoether, citraconic acid, citraconic acid monoalkyl ester, andcinnamic acid.(3) Sulfone group-containing vinyl monomers, vinylsulfuric acidmonoester compounds and their salts: e.g., alkenesulfonic acid having 2to 14 carbon atoms such as vinylsulfonic acid, (meth)allylsulfonic acid,methylvinylsulfonic acid, and styrenesulfonic acid; their alkyl (having2 to 24 carbon atoms) derivatives such as α-methylstyrenesulfonic acid;sulfo(hydroxy)alkyl(meth)acrylates or (meth)acrylamides such assulfopropyl(meth)acrylate, 2-hydroxy-3-(meth)acryloxypropylsulfonicacid, 2-(meth)acryloylamino-2,2-dimethylethanesulfonic acid,2-(meth)acryloyloxyethanesulfonic acid,3-(meth)acryloyloxy-2-hydroxypropanesulfonic acid,2-(meth)acrylamido-2-methylpropanesulfonic acid,3-(meth)acrylamido-2-hydroxypropanesulfonic acid, alkyl (having 3 to 18carbon atoms)-allylsulfosuccinic acid, poly(n=2 to 30)oxyalkylene(ethylene, propylene, and butylene: mono, random, or block)mono(meth)acrylate sulfuric acid esters [poly(n=5 to 15)oxypropylenemonomethacrylate sulfuric acid esters], polyoxyethylene polycyclicphenyl ether sulfuric acid ester, and sulfuric acid esters or sulfonicacid group-containing monomers defined by the following formulas (1-1)to (1-3); and their salts:

wherein R denotes an alkyl having 1 to 15 carbon atoms; A denotes analkylene having 2 to 4 carbon atoms and may be same or different in thecase n is plural and in the case of different alkylenes, they may berandom or block form; Ar denotes a benzene ring; n denotes an integer of1 to 50; R′ denotes a fluorine-substituted or unsubstituted alkylenehaving 1 to 15 carbon atoms.(4) Phosphoric acid group-containing vinyl monomers and their salts:(meth)acryloyloxyalkyl (C1 to C24) phosphoric acid monoesters such as2-hydroxyethyl(meth)acryloylphosphate,phenyl-2-acryloyloxyethylphosphate, (meth)acryloyoxyalkyl (C1 toC24)-sulfonic acid such as 2-acryloyloxyethylphosphonic acid.

As the salts of the above-exemplified compounds (2) and (4) may beincluded metal salts, ammonium salts, and amine salts (includingquaternary ammonium salts). The metals to form the metal salts are Al,Ti, Cr, Mn, Fe, Zn, Ba, Zr, Ca, Mg, Na, and K. Alkali metal salts andamine salts are preferable and sodium salts and salts of tertiarymonoamine having 3 to 20 carbon atoms are more preferable.

(5) Hydroxyl-containing vinyl monomers: hydroxystyrene,N-methylol(meth)acrylamide, hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, polyethylene glycol mono(meth)acrylate,(meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol,2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethylpropenyl ether, and sucrose allyl ether.(6) Nitrogen-containing vinyl monomers:(6-1) amino group-containing vinyl monomers: aminoethyl (meth)acrylate,dimethylaminoethyl(meth)acrylate, diethylaminoethyl(meth)acrylate,tert-butylaminoethyl methacrylate, N-aminoethyl(meth)acrylamide,(meth)allylamine, morpholinoethyl(meth)acrylate, 4-vinylpyridine,2-vinylpyridine, crotylamine, N,N-dimethylaminostyrene, methylα-acetoaminoacrylate, vinylimidazole, N-vinylpyrrole,N-vinylthiopyrrolidone, N-arylphenylenediamine, aminocarbazole,aminothiazole, aminoindole, aminopyrrole, aminoimidazole,aminomethylcaptothiazole, and their salts;(6-2) amido group-containing vinyl monomers: (meth)acrylamide,N-methyl(meth)acrylamide, N-butylacrylamide, diacetoneacrylamide,N-methylol(meth)acrylamide, N,N′-methylene-bis(meth)acrylamide, sinnamicacid amide, N,N-dimethylacrylamide, N,N-dibenzylacrylamide,methacrylformamide, N-methyl-N-vinylacetamide, and N-vinylpyrrolidone;(6-3) nitryl group-containing vinyl monomers: (meth)acrylonitrile,cyanostyrene, and cyanoacrylate;(6-4) quaternary ammonium cation group-containing vinyl monomers:quaternary compounds (quaternalized by using quaternarization agentssuch as methyl chloride, dimethyl sulfric acid, benzyl chloride,dimethyl carbonate) of tertiary amine group-containing vinyl monomerssuch as dimethylaminoethyl(meth)acrylate, diethylaminoethyl(meth)acrylate, dimethylaminoethyl(meth)acrylamide, anddiethylaminoethyl(meth)acrylamide, diallyl amine; and(6-5) nitro group-containing vinyl monomer: nitrostyrene.(7) Epoxyl-containing vinyl monomers: glycidyl(meth)acrylate,tetrahydrofurfuryl(meth)acrylate, p-vinylphenylphenyl oxide,(8) halogen-containing vinyl monomers: vinyl chloride, vinyl bromide,vinylidiene chloride, acryl chloride, chlorostyrene, bromostyrene,dichlorostyrene, chloromethylstyrene, tetrafluorosthylene andchloroprene.(9) Vinyl esters, vinyl(thio)ethers, vinyl ketones, and vinyl sulfones:(9-1) vinyl esters: e.g., vinyl acetate, vinyl butyrate, vinylpropionate, vinyl butyrate, diallyl phthalate, diallyl adipate,isopropenyl acetate, vinyl methacrylate, methyl 4-vinylbenzoate,cyclohexyl methacrylate, benzyl methacrylate, phenyl(meth)acrylate,vinylmethoxy acetate, vinyl benzoate, ethyl α-ethoxyacrylate,alkyl(meth)acrylate having alkyl with 1 to 50 carbon atoms [e.g.,methyl(meth)acrylate, ethyl (meth)acrylate, propyl(meth)acrylate,butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, dodecyl(meth)acrylate,hexadecyl (meth)acrylate, heptadecyl(meth)acrylate, and eicosyl(meth)acrylate], dialkyl fumarate (the two alkyl groups may be linear,branched, or alicyclic alkyls having 2 to 8 carbon atoms), dialkylmaleate (the two alkyl groups may be linear, branched, or alicyclicalkyls having 2 to 8 carbon atoms), poly(meth)acryloxyalkanes [e.g.diaryloxyethane, triaryloxyethane, tetraaryloxyethane,tetraaryloxypropane, tetraaryloxybutane, and tetrametharyloxyethane],polyalkylene glycol chain-containing vinyl monomers [e.g., polyethyleneglycol (molecular weight 300) mono(meth)acrylate, polypropylene glycol(molecular weight 500) monoacrylate, methyl alcohol ethylene oxide(hereinafter, ethylene oxide is abbreviated as EO) 10 mole adduct(meth)acrylate, and lauryl alcohol EO 30 mole adduct (meth)acrylate],poly(meth)acrylates [e.g. polyhydric alcohol poly(meth)acrylates such asethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate,neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate,and polyethylene glycol di(meth)acrylate];(9-2) vinyl(thio) ethers such as vinyl methyl ether, vinyl ethyl ether,vinyl propyl ether, vinyl butyl ether, vinyl 2-ethylhexyl ether, vinylphenyl ether, vinyl 2-methoxyethyl ether, methoxybutadiene, vinyl2-butoxyethyl ether, 3,4-dihydro-1,2-pyrane, 2-butoxy-2′-vinyloxydiethyl ether, vinyl 2-ethylmercaptoethyl ether, acetoxystyrene, andphenoxystyrene;(9-3) vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, andvinyl phenyl ketone; andvinyl sulfones such as divinyl sulfide, p-vinyl diphenyl sulfide, vinylethyl sulfide, vinyl ethyl sulfone, divinyl sulfone, and divinylsulfoxide.(10) Other vinyl monomers: isocyanatoethyl(meth)acrylate,m-isopropenyl-α,α-dimethylbenzyl isocyanate.

In the fourth invention, in the case a vinyl resin containing aconstituent unit of an organic acid metal salt (m) as (a), the resin isobtained by using one or more kinds of metal salts selected from Al, Ti,Cr, Mn, Fe, Zn, Ba, and Zr of the above-mentioned monomers (2) to (4) asat least some of the monomers. The use amount of these organic acidmetal salt monomers (m) in the entire monomers to be used is preferably5 to 60%. The lower limit is more preferably 10% and the upper limit ismore preferably 50%.

The copolymers of the vinyl monomers may include polymers obtained bycopolymerizing properly selected two or more kinds of monomers of theabove-exemplified (1) to (10) at optional ratios preferably so as toadjust the content of the carboxyl groups in the resin particles (A) tobe 0.1 to 10% and examples are styrene-(meth)acrylic acidester-(meth)acrylic acid copolymer, styrene-butadiene-(meth)acrylic acidcopolymer, (meth)acrylic acid-acrylic acid ester copolymer,styrene-acrylonitrile-(meth)acrylic acid copolymer,styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylicacid-divinylbenzene copolymer, styrene-styrenesulfonicacid-(meth)acrylic acid ester copolymer, and salts of these copolymers.

In the case the resin (a) forms the resin particles (A) in thewater-based dispersion (X1), it is required for the resin (a) not to bedissolved completely at least in the condition in which (X1) isproduced. Therefore, in the case the vinyl resin is a copolymer, theratio of the hydrophobic monomer and the hydrophilic monomer composingthe vinyl resin is generally preferably 10% or higher and morepreferably 30% or higher for the hydrophobic monomer although it dependson the types of the selected monomers. If the ratio of the hydrophobicmonomer is lowered to 10% or less, the vinyl resin becomes water-solubleand the evenness of the particle diameter of (C) is deteriorated.Herein, a hydrophilic monomer means a monomer dissolved at an optionalratio in water and a hydrophobic monomer include monomers other thanthat (monomers basically having no affinity to water).

Polyester resins may include condensation polymers of polyols withpolycarboxylic acid, their anhydrides, or their lower alkyl esters, andmetal salts of these condensation polymers. Polyols may include diol(11) and tri- to octa- or higher hydric polyol (12) and polycarboxylicacids, their anhydrides, or their lower alkyl esters may includedicarboxylic acid (13) and tri- to hexa- or higher valent polycarboxylicacid (14), their anhydrides, or their lower alkyl esters.

The ratio of the polyol and the polycarboxylic acid on the basis of theequivalent ratio [OH]/[COOH] of the hydroxyl [OH] and carboxyl [COOH] ispreferably in a range from 2/1 to 1/5, more preferably in a range from1.5/1 to 1/4, and even more preferably in a range from 1/1.3 to 1/3.

To adjust the content of the carboxyl group within the above-mentionedpreferable range, a polyester having an excess amount of hydroxy groupmay be treated with a polycarboxylic acid.

The diols (11) may include alkylene glycols (e.g., ethylene glycol,1,2-propoylene glycol, 1,3-propylene glycol, 1,4-butanediol,1,6-hexandiol, octanediol, decanediol, dodecanediol, tetradecanediol,neopentyl glycol, and 2,2-diethyl-1,3-propanediol); alkylene etherglycols having 4 to 36 carbon atoms (e.g., diethylene glycol,triethylene glycol, dipropylene glycol, polyethylene glycol,polypropylene glycol, and polytetramethylene ether glycol); alicyclicdiols having 4 to 36 carbon atoms (e.g., 1,4-dicyclohexanedimethanol andhydrogenated bisphenol A); alkylene oxide (hereinafter, abbreviated asAO) [e.g., EO and propylene oxide (hereinafter, abbreviated as PO),butylene oxide (hereinafter, abbreviated as BO)] adducts (addition molenumber: 1 to 120) of the above-mentioned alkylene glycols or alicyclicdiols; AO (EO, PO, and BO) adducts (addition mole number: 2 to 30) ofbisphenols (e.g. bisphenol A, bisphenol F, and bisphenol S); polylactonediols (e.g. poly(ε-caprolactone diol)); and polybutadiene diol.

The diols may include diols (11a) having another functional group otherthan the above-mentioned diols having no functional group excepthydroxyl. Examples of (11a) are diols having carboxyl, diols havingsulfonic acid group or sulfamic acid group, and their salts.

Diols having carboxyl may include dialkylol alkanoic acids [of C6-24,e.g., 2,2-dimethylolpropionic acid (DMPA), 2,2-dimethylolbutanoic acid,2,2-dimethylolheptanoic acid, and 2,2-dimethyloloctanoic acid].

Diols having sulfonic acid group or sulfamic acid group may includesulfamic acid dials [e.g., N,N-bis(2-hydroxyalkyl)sulfamic acid (C1-6alkyl) or its AO adducts (AO may be EO or PO: addition mole number of AOis 1 to 6) such as N,N-bis(2-hydroxyethyl)sulfamic acid andN,N-bis(2-hydroxyethyl)sulfamic acid PO 2 mole adduct]; andbis(2-hydroxyethyl)phosphate.

Neutralizing base groups of these diols having the neutralizing basegroups may include, for example, the above-mentioned tertiary amineshaving 3 to 30 carbon atoms (e.g., triethylamine) and/or alkali metals(e.g., sodium salt).

Among them are alkylene glycol having 2 to 12 carbon atoms, diols havingcarboxyl, AO adducts of bisphenols, and their combinations preferable.

Polyols (12) may include tri- to octa- or higher polyhydric aliphaticalcohols having 3 to 36 carbon atoms (e.g., alkane polyols and theirinternal or intermolecular dehydrates such as glycerin,trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol,sorbitan, and polyglycerin; saccharides and their derivatives such assucrose and methyl glycoside); polyhydric aliphatic alcohol AO adducts(addition mole number: 2 to 120); trisphenols (e.g., trisphenol PA) AOadducts (addition mole number: 2 to 30); novolak resins (e.g., phenolnovolak, cresol novolak) AO adducts (addition mole number: 2 to 30); andacrylic polyols [e.g., copolymers of hydroxyethyl (meth)acrylate andother vinyl monomers].

Among them are tri- to octa- or higher polyhydric aliphatic alcohols andnovolak resin AO adducts preferable and especially novolak resin AOadducts more preferable.

Dicarboxylic acids (13) may include alkanedicarboxylic acids having 4 to36 carbon atoms (e.g., succinic acid, adipic acid, sebacic acid, azelaicacid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, anddecylsuccinic acid) and alkenylsuccinic acids (e.g., dodecenylsuccinicacid, pentadecenylsuccinic acid, and octadecenylsuccinic acid);alicyclic dicarboxylic acids having 6 to 40 carbon atoms [e.g., dimmeracid (dimerization linoleic acid)]; alkenedicarboxylic acids having 4 to36 carbon atoms (e.g., maleic acid, fumaric acid, and citraconic acid);aromatic dicarboxylic acids having 8 to 36 carbon atoms (e.g., phthalicacid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylicacid). Preferable examples among them are alkanedicarboxylic acidshaving 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to20 carbon atoms.

Tri- to hexa- or higher valent polycarboxylic acids (14) may includearomatic polycarboxylic acids having 9 to 20 carbon atoms (trimelliticacid and pyromellitic acid).

As dicarboxylic acids (13) or tri- to hexa- or higher valentpolycarboxylic acids (14), acid anhydrides of the above-mentionedexamples or their esters of lower alkyl having 1 to 4 carbon atoms(e.g., methyl ester, ethyl ester, and isopropyl ester) may be used.

In the fourth invention, in the case a polyester resin containing aconstituent unit of the organic acid metal salt (m) as (a), the resinis, for example, obtained by synthesizing a polyester (having an acidvalue preferably in a range of 1 to 100 and more preferably in a rangefrom 5 to 50) having COOH residual groups and making at least some ofthe COOH groups to be a salt of at least one metal selected from Al, Ti,Cr, Mn, Fe, Zn, Ba, and Zr.

A method for making a metal salt may be carried out by reaction of thepolyester having COOH groups with the corresponding metal hydroxide.

The epoxy resins may include ring opening polymers of polyepoxides (18),addition polymers of polyepoxides (18) and active hydrogen-containingcompounds (D) {water, polyols [above-mentioned diols (11) and tri- andhigher hydric polyols (12)], dicarboxylic acids (13), tri and highervalent polycarboxylic acids (14), polyamines (16) which will bementioned later, and polythiols (17) which will be mentioned later}, orcured products of polyepoxides (18) with dicarboxylic acids (13) and triand higher valent polycarboxylic acid (14) anhydrides.

The polyepoxides (18) of the invention are not particularly limited ifthey have two or more epoxy groups in the molecule. Preferable examplesof the polyepoxides (18) are those having 2 to 6 epoxy groups in amolecule in terms of mechanical properties of cured products. The epoxyequivalent (molecular weight per one epoxy group) of the polyepoxides(18) is generally 65 to 1000 and preferably 90 to 500. If the epoxyequivalent exceeds 1000, the cross-linked structure becomes loose andthe physical properties such as water resistance, chemical resistance,and mechanical strength of the cured products are worsened and on theother hand, it is difficult to synthesize those having epoxy equivalentless than 65.

Examples of the polyepoxides (18) are aromatic polyepoxy compounds,heterocyclic polyepoxy compounds, alicyclic polyepoxy compounds, oraliphatic polyepoxy compounds. Examples of the aromatic polyepoxycompounds are glycidyl esters and glycidyl ethers of polyhydric phenols,glycidyl aromatic polyamines, and glycidyl compounds of aminophenol.Examples of polyhydric phenol glycidyl ethers are bisphenol F diglycidylether, bisphenol A diglycidyl ether, bisphenol B diglycidyl ether,bisphenol AD diglycidyl ether, bisphenol S diglycidyl ether, halogenatedbisphenol A diglycidyl ether, tetrachlorobisphenol A diglycidyl ether,catechin diglycidyl ether, resorcinol diglycidyl ether, hydroquinonediglycidyl ether, pyrogallol triglycidyl ether, 1,5-dihydroxynapthalinediglycidyl ether, dihydroxybiphenyl diglycidyl ether,octachloro-4,4′-dihydroxybiphenyl diglycidyl ether, tetramethylbiphenyldiglycidyl ether, dihydroxynaphthyl cresol triglycidyl ether,tris(hydroxyphenyl)methane triglycidyl ether, dinaphthyltrioltriglycidyl ether, tetrakis(4-hydroxyphenyl)ethane tetraglycidyl ether,p-glycidylphenyldimethyltolyl bisphenol A glycidyl ether,trismethyl-tert-butyl-butylhydroxymethane triglycidyl ether,9,9′-bis(4-hydroxyphenyl)fluorene diglycidyl ether,4,4′-oxybis(1,4-phenylethyl)tetracresol diglycidyl ether,4,4′-oxybis(1,4-phenylethyl)phenyl glycidyl ether,bis(dihydroxynaphthalene) tetraglycidyl ether, phenol or cresol novolakresin glycidyl ethers, limonene phenol novolak resin glycidyl ethers,diglycidyl ethers obtained by reaction of 2 mole of bisphenol A and 3mole epichlorohydrin, polyglycidyl ethers of polyphenols obtained bycondensation reaction of phenol with glyoxal, glutaraldehyde, orformaldehyde, and polyglycidyl ethers of polyphenols obtained bycondensation reaction of resorcin and acetone. Examples of thepolyglycidyl esters of polyphenols are phthalic acid diglycidyl ester,isophthalic acid diglycidyl ester, and terephthalic acid diglycidylester. Examples of the glycidyl aromatic polyamines areN,N-diglycidylaniline, N,N,N′,N′-tetraglycidylxylylenediamine, andN,N,N′,N′-tetraglycidyldiphenylmethanediamine. Further, in theinventions, p-aminophenol triglycidyl ether, diglycidylurethanecompounds obtained by addition reaction of tolylene diisocyanate ordiphenylmethane diisocyanate with glycidol, and diglycidyl ethers ofalkylene oxide (e.g., ethylene oxide or propylene oxide) adducts ofglycidyl-containing polyurethane (pre)polymers and bisphenol A obtainedby reaction of the former two reaction products with polyols are alsoincluded as the aromatic polyepoxy compounds. The heterocyclic polyepoxycompounds may include trisglycidylmelamine. Examples of the aliphaticpolyethoxy compounds are vinylcyclohexene dioxide, limonene dioxide,dicyclopentadiene dioxide, bis(2,3-epoxycyclopentyl) ether, ethyleneglycol bisepoxydicyclopentyl ether,3,4-epoxy-6-methylcyclohexylmethyl-3′,4′-epoxy-6′-methylcyclohexanecarboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate,bis(3,4-epoxy-6-methylcyclohexylmethyl) butylamine, and dimer aciddiglycidyl esters. Examples of the alicyclic type compounds may includethose obtained by nuclear-hydrogenation of the above-mentioned aromaticpolyepoxide compounds and examples of aromatic polyepoxy compounds arepolyglycidyl ethers of aliphatic polyhydric alcohols, polyglycidylesters of aliphatic polyfatty acids, and aliphatic glycidyl amines.Examples of the polyglycidyl ethers of the aliphatic polyhydric alcoholsare ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether,tetramethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether,polyethylene glycol diglycidyl ether, polypropylene glycol diglycidylether, polytetramethylene glycol diglycidyl ether, neopentyl glycoldiglycidyl ether, trimethylolpropane polyglycidyl ether, glycerolpolyglycidyl ether, pentaerythritol polyglycidyl ether, sorbitolpolyglycidyl ether, and polyglycerol polyglycidyl ether. Examples of thepolyglycidyl ethers of polyfatty acids are diglycidyl oxalate,diglycidyl maleate, diglycidyl succinate, diglycidyl glutarate,diglycidyl adipate, and diglycidyl pimelate. The aliphatic glycidylamines may include N,N,N′,N′-tetraglycidylhexamethylenediamine. Further,in the inventions, the aliphatic type compounds may also includediglycidyl ethers and glycidyl(meth)acrylate (co)polymers. Thosepreferable among them are aliphatic polyethoxy compounds and aromaticpolyepoxy compounds. Two or more kinds of the polyepoxides may be useused in combination in the inventions.

Resins satisfying the conditions of the first (the third invention aswell), and the second inventions are preferable for the resin (a) and inthe case the electrostatic property is regarded as one of importantfactors, it is preferable for the resins to satisfy the conditions ofthe fourth invention as well.

In the fourth invention, other than the method of using theabove-mentioned resin (a) into which the organic acid salts (m) ofmetals selected from Al, Ti, Cr, Mn, Fe, Zn, Ba, and Zr is introduced,(m) may be added to the resin particles (A) to obtain the water-baseddispersion of the fourth invention. Further, the method may also be usedin which the resin particles (A) obtained by using above-mentionedmethods in combination are used.

Practical examples to be used preferably as the carboxylic acid metalsalts among the organic acid metal salts (m) may be those exemplified asthe metal salts of aromatic fatty acids having 7 to 35 carbon atoms suchas (alkyl-substituted) benzoic acids, (alkyl-substituted) salicylicacids, and naphthenic acid, higher fatty acids having 12 to 35 carbonatoms such as stearic acid, and the above-mentioned carboxyl-containingvinyl monomers. Practical examples to be used preferably as the sulfonicacid metal salts are those exemplified as the metal salts ofalkylbenzenesulfonic acids having 7 to 30 carbon atoms and sulfonegroup-containing vinyl monomers composing the vinyl resins. Examples tobe used preferably as the phosphoric acid metal salts are thoseexemplified as the metal salts of the phosphoric acid group-containingvinyl monomers composing the vinyl resins. Among them, oil-soluble metalsalts are more preferable in terms of the exhibition of electrostaticproperty of the resin particles (C). In terms of the composition,carboxylic acid metal salts are more preferable and Zn salts and Fesalts of carboxylic acids are particularly more preferable.

A method of adding the organic acid metal salts (m) to (A) may becarried out by loading it before production of (a) if there is noreactivity with the precursor of the resin (a), however it is preferableto mix them with (a) after the production of (a).

The use ratio of the constituent units of these organic acid metal salts(m) and the organic acid metal salts (m) is not particularly limited,however it is preferable to be 0.01 to 10% in the total of them to theresin particles (C1) to be obtained. The lower limit is more preferably0.05% and the upper limit is more preferably 1%.

The core-shell type resin particles (C2) of the first invention may beresin particles produced by any method and process and a method ofproducing the core-shell type resin particles may be the followingproduction methods (I) to (III).

(I): Production method for forming core-shell structure simultaneouslywith core particles production

A method of dispersing a resin (b) [including its precursor (b0)] or itssolvent solution in a water-based dispersion (W) of the resin particles(A) comprising a resin (a) and thereby forming the resin particles (B)comprising (b) in (W). In this case, simultaneously with the granulationof resin particles (B), the resin particles (A) adhere to the surface of(B) and a water-based dispersion (X1) of core-shell type resin particles(C1) is obtained and the core-shell type resin particles are obtained byremoving the water-based solvent from the dispersion. In this case, ifthe surfaces of (C1) are not formed in a film-like form, the treatmentfor making a film-like form may be carried out and this process may becarried out in any step after production of (X1).

(II): Production method for forming core-shell type resin particles (C2)by coating previously produced resin particles (B) comprising the resin(b) with a coating agent (W′) comprising the resin (a) and furthermaking the shell layer in form of a film if necessary. In this case, thecoating agent (W′) may be in any phase such as a liquid or solid or thelike and further may be applied a precursor (a′) of (a) for coating andthen subjected to reaction to convert (a′) into (a). (B) to be used maybe resin particles produced by any production method, for example, resinparticles produced by an emulsion polymerization and coagulation methodor resin particles produced by a pulverization method. The coatingmethod is not particularly limited and a method of dispersing previouslyproduced resin particles (B) or dispersion of (B) in the water-baseddispersion (W) of the resin particles (A) comprising the resin (a) and amethod of spraying an resin (a)-dissolved solution as a coating agent to(B) may be exemplified.(III): Production method for producing core particles and converting thesurface peripheries of the core particles into another shell resin byphysical and/or chemical operation. A method of previously producing theresin particles (B) comprising the resin (b) and treating the surfacesof the particles (B) by heating and/or chemical treatment (with an acidor amine neutralization) to convert the mono-structure particles (B)into core-shell type resin particles (C2) can be exemplified.

Among them is the production method (I) preferable.

In the second, third, fourth, eighth, and tenth inventions and theabove-mentioned production method (I) in the first invention, at thetime of forming the resin particles (B) from the resin (b) by dispersing(b) or its solvent solution, alternatively a precursor (b0) of (b) orits solvent solution in the water-based dispersion (W) of the resinparticles (A) comprising the resin (a) and if necessary an organic acidmetal salt (m), the resin particles (A) are adsorbed on the surfaces ofthe resin particles (B) to prevent agglomeration of the resin particles(C1) one another and make (C1) difficult to be pulverized under highshearing condition. Accordingly, the particle diameters of (C1) areconverged into a constant value and the evenness of the particlediameters is improved. Therefore, the resin particles (A) are preferableto have a strength high enough to avoid breakage by shearing at thetemperature at the time of dispersion, to be hard to be dissolved inwater or swollen with water, and to be hard to be dissolved in (b) orits solvent solution, (b0) or its solvent solution.

In the second invention, the sp value of the resin particles (A) to theresin particles (B) (the calculation method of sp value is according tothe method described in Polymer Engineering and Science, February, 1974,vol. 14, No. 2. P. 147-154) and the molecular weight of the resinparticles (A) are controlled to smooth the particle surfaces of theresin particles (C1).

In the second invention, resin (a) and resin (b) are selected so as tokeep the point (K, H) within an area surrounded by a quadrangle definedby the following four points A, B, C, and D including the side lines ina system of K, H coordinates as shown in FIG. 1, wherein K denotes spvalue difference (Δsp) of (a) and (b) and H denotes the naturallogarithm ln(Mw) of the weight average molecular weight (Mw) of resin(a): A (0.3, ln 3000), B (1.5, ln 1000), C (1.3, ln 200000), and D (0.1,ln 200000).

The point (K, H) is more preferably within an area surrounded by aquadrangle defined by the following four points A′, B′, C′, and D′including the sidelines and even more preferably within an areasurrounded by a quadrangle defined by the following four points A′, B′,C′, and D′ including the side lines:

A′ (0.3, ln 3200), B′ (1.45, ln 1500), C′ (1.3, ln 10000), and D′ (0.15,ln 100000) and A″ (0.3, ln 3400), B″ (1.4, ln 2000), C″ (1.3, ln 50000),and D″ (0.2, ln 50000).

In the case the point (K, H) exists below the straight line AB, at thetime of granulation, the resin particles (A) become easy to be dissolvedin a solvent or the like and granulation may not be carried out well insome cases. Also, in the case the point (K, H) exists above the straightline CD, the resin particles (A) are not at all swollen with a solventor the like and become hard to be thermally melted and therefore, thesmoothness of the resin particles (C1) becomes insufficient to result indecrease of powder flowability in some cases. In the case the point (K,H) exists in the left of the straight line AD, since the sp valuedifference between the resin (a) and the resin (b) is so small as todissolve the resin particles (A) in the solution of the resin (b),resulting in granulation difficulty. Further, in the case the point (K,H) exists in the right of the straight line BC, since the sp valuedifference between the resin (a) and the resin (b) is so big as to makethe resin particles (A) completely unswollable in a solvent, resultingin insufficiency of the smoothness of the particles and decrease offlowability and in the case the point (K, H) is in further right, thatis the sp value difference between the resin (a) and the resin (b)becomes bigger, the attraction power of the resin particles (A) to theresin particles (B) is decreased to lead to granulation difficulty.

In term of the suppression of dissolution or swelling of the resinparticles (A) in water or a solvent to be used in the case ofdispersion, it is preferable to properly adjust the molecular weight, spvalue, crystallization property, and inter-crosslinking point molecularweight of the resin (a).

The number average molecular weight (measured by gel permeationchromatography, hereinafter, referred to as Mn) of the resin (a) isgenerally 100 to 5,000,000, preferably 200 to 5,000,000, and morepreferably 500 to 500,000, and the sp value is generally 7 to 18 andpreferably 8 to 14. The melting point of the resin (a) (measured by DSC)is generally 50° C. or higher and preferably 80 to 200° C. In the casethe thermal resistance, water-resistance, chemical resistance, andevenness of the particle diameter of the resin particles (C) are to beimproved, crosslinking structure may be introducing into the resin (a).Such crosslinking structure may be any crosslinking structure based oncovalent bonding, coordination bonding, ion bonding, hydrogen bonding orthe like. The inter-crosslinking point molecular weight in the case ofintroducing the crosslinking structure into the resin (a) is generally50 or higher, preferably 500 or higher, and more preferably 1000 orhigher.

In the present invention, the number average molecular weight (Mn) andthe weight average molecular weight (Mw) of the resin are valuesmeasured by Gel Permeation Chromatography (GPC) with respect to atetrahydrofuran (THF)-soluble portion of the resin under the followingmeasurement conditions:

Apparatus (for an example): HLC-8120 manufactured by Tosoh

Column (for an example): TSKgelGMHXL (two of them)

-   -   TSKgelMultiporeHXL-M (one of them)        Sample solution: a THF solution of 0.25% concentration        Volume of solution injected: 1001        Flow rate: 1 ml/min.        Measurement temperature: 40° C.        Detector: refractive index detector        Standard substance: standard polystyrene manufactured by Tosoh        (TSKstandard POLYSTYRENE) twelve (12) points (Mw 500 1050 2800        5970 9100 18100 37900 96400 190000 355000 1090000 2890000)

Also, Mn and Mw of polyurethane resins usable for the resin (b)mentioned after are values measured by GPC under the followingmeasurement conditions:

Apparatus (for an example): HLC-8220GPC manufactured by Tosoh

Column (for an example): Guardcolumn α

-   -   TSKgel α-M        Sample solution: a dimethylformamide solution of 0.125%        concentration        Volume of solution injected: 100 μl        Flow rate: 1 ml/min.        Measurement temperature: 40° C.        Detector: refractive index detector        Standard substance: standard polystyrene manufactured by Tosoh        (TSKstandard POLYSTYRENE) twelve (12) points (Mw 500 1050 2800        5970 9100 18100 37900 96400 190000 355000 1090000 2890000)

The glass transition temperature (Tg) of the resin (a) is generally 20°C. to 250° C., preferably 30° C. to 230° C., more preferably 40° C. to200° C., and even more preferably 50° C. to 100° C. in terms of theparticle diameter evenness, powder flowability, thermal resistance atthe time of storage, and stress resistance of the resin particles (C).If the Tg is lower than the temperature at which the water-baseddispersion (X1) is produced, the effect to prevent agglomeration orbreakdown is lessened and the effect to improve the evenness of theparticle diameter is lessened.

Further, for the same reason, Tg of the resin particles (A) comprising(a) and if necessary (m) is preferably 20 to 200° C., more preferably 30to 100° C., and even more preferably 40 to 80° C.

Tg in the invention is a value measured by DSC measurement or flowtester measurement (in the case measurement by DSC is impossible).

An overhead type flow tester CFT 500 model manufactured by ShimadzuCorp. is employed for the flow tester measurement. The conditions of theflow tester measurement are as follows and hereinafter, the measurementis all carried out under these conditions.

(Flow Tester Measurement Conditions)

Load: 30 kg/cm²; heating speed: 3.0° C./min; die diameter: 0.50 mm; anddie length: 10.0 mm.

Also, A point in the flow chart shown in FIG. 2 (the temperature atwhich a sample receives a compressive load and starts deforming) isdefined to be the glass transition temperature (Tg): B point (thetemperature at which the inner voids disappear and a single transparentbody or phase with uniform appearance while keeping uneven stressdistribution is produced) is defined to be an initial softeningtemperature (Ts): C point (the temperature at which a piston againstarts descending after the piston is slightly elevated owing to thermalexpansion of a sample) is defined to be the flow starting temperature(Tfb): and D point (the temperature at the point determined bycalculating ½ of the difference between Smax at the flow finishing pointand the minimum value 5 min in Fig. and adding X and 5 min) is definedas the flow temperature (T1/2).

In terms of the thermal resistance at the time storage, stressresistance, and fixing property on a paper sheet or the like, theinitial softening temperature (Ts) of the resin (a) is preferably 40° C.to 270° C., more preferably 50° C. to 250° C., furthermore preferably60° C. to 220° C., and even more preferably 70° C. to 160° C.: the flowtemperature (T1/2) is preferably 60° C. to 300° C., more preferably 65°C. to 280° C., furthermore preferably 70° C. to 250° C., and even morepreferably 80° C. to 180° C. In the case of using the resin particlesfor a toner, if the initial softening temperature (Ts) and flowtemperature (T1/2) are high temperature, it may results in inferiorityof low temperature fixing property and high luster. The initialsoftening temperature and the flow temperature in the invention arevalues measured by the above-mentioned flow tester measurement.

The temperature difference of the glass transition temperature (Tg) andthe flow temperature (T1/2) of the resin (a) is preferably 0° C. to 120°C., more preferably 0° C. to 100° C., furthermore preferably 0° C. to90° C., and even more preferably 0° C. to 80° C. If the temperaturedifference of the glass transition temperature and the flow temperatureis within the above-mentioned range, in the case the resin particles areused for a toner, it becomes easy to simultaneously satisfy both of thethermal resistance at the time of storage and high luster of the resinparticles.

The temperature difference of the glass transition temperature (Tg) andthe initial softening temperature (Ts) of the resin (a) is preferably 0°C. to 100° C., more preferably 0° C. to 70° C., furthermore preferably0° C. to 50° C., and even more preferably 0° C. to 35° C. If thetemperature difference of the glass transition temperature and theinitial softening temperature is within the above-mentioned range, inthe case the resin particles are used for a toner, it becomes easy tosimultaneously satisfy both of the thermal resistance at the time ofstorage and high luster of the resin particles.

The resin (a) to be used in the first and the third invention is a resinhaving all of an initial softening temperature in a range of 40 to 270°C., a glass transition temperature in a range of 20 to 250° C., a flowtemperature in a range of 60 to 300° C., and the difference of the glasstransition temperature and the flow temperature in a range of 0 to 120°C.

With respect to the Shore D hardness, which is a standardized hardness,the hardness of the resin particles (A) is generally 30 or higher andparticularly preferably in a range of 45 to 100. Further, even in thecase of immersion in water or in a solvent for a prescribed time, thehardness is preferable to be within the above-mentioned range.

The water-based dispersion (W) of the resin particles (A) may contain asolvent (e.g., acetone, methyl ethyl ketone, or the like) havingaffinity to water among solvents (u) described below other than water.In this case, the solvent to be added may be any solvent if it is thatwhich does not cause agglomeration of the resin particles (A), whichdoes not dissolve the resin particles (A), and which does not preventthe granulation of the resin particles (C1) and the content may also beoptional, however it is preferable to use the amount of 40% or lowerbased on the total content of water and the solvent and it does notremain in the resin particles (C1) after drying.

A method for obtaining the water-based dispersion of the resin particles(A) from a resin (a) is not particularly limited and the followingmethods [1] to [8] can be exemplified.

[1] In the case of vinyl resins, a method of directly producing thewater-based dispersion of the resin particles (A) by polymerizationreaction such as a suspension polymerization method, an emulsificationpolymerization method, a seed polymerization method or a dispersionpolymerization method from monomers as starting raw materials.[2] In the case of addition polymerization or condensation type resinssuch as polyester resins, a method of dispersing a precursor (a monomer,an oligomer, and the like) or its solvent solution in a water-basedsolvent if necessary in the presence of a dispersant and thereaftercarrying out curing step by heating or adding a curing agent to producethe water-based dispersion of the resin particles (A).[3] In the case of addition polymerization or condensation type resinssuch as polyester resins, a method of dissolving a proper emulsifier ina precursor (a monomer, an oligomer, and the like) or its solventsolution (it is preferable to be a liquid. It may be liquefied byheating.), successively adding water for phase inversion emulsification,and carrying out curing by adding a curing agent to produce thewater-based dispersion of the resin particles (A).[4] A method of pulverizing a resin previously, which is produced bypolymerization reaction (any polymerization reaction manner such asaddition polymerization, ring-opening polymerization, polyaddition,addition condensation polymerization, and condensation polymerization),by mechanically rotating or jet type pulverizer, classifying thepulverized resin for obtaining resin particles, and dispersing the resinparticles in water in the presence of a proper dispersant.[5] A method of previously producing a resin by polymerization reaction(any polymerization reaction manner such as addition polymerization,ring-opening polymerization, polyaddition, addition condensationpolymerization, and condensation polymerization), dissolving theobtained resin in a solvent, spraying the resin solution in atomizedstate for obtaining resin particles, and dispersing the resin particlesin water in the presence of a proper dispersant.[6] A method of previously producing a resin by polymerization reaction(any polymerization reaction manner such as addition polymerization,ring-opening polymerization, polyaddition, addition condensationpolymerization, and condensation polymerization), dissolving theobtained resin in a solvent for obtaining a resin solution, eitheradding a poor solvent to the resin solution or cooling the resinsolution for precipitating the resin particles, removing the solvent forobtaining the resin particles, and dispersing the resin particles inwater in the presence of a proper dispersant.[7] A method of previously producing a resin by polymerization reaction(any polymerization reaction manner such as addition polymerization,ring-opening polymerization, polyaddition, addition condensationpolymerization, and condensation polymerization), dissolving theobtained resin in a solvent for obtaining a resin solution, dispersingthe resin solution in water in the presence of a proper dispersant, andremoving the solvent by heating or reducing pressure.[8] A method of previously producing a resin by polymerization reaction(any polymerization reaction manner such as addition polymerization,ring-opening polymerization, polyaddition, addition condensationpolymerization, and condensation polymerization), dissolving theobtained resin in a solvent for obtaining a resin solution, dissolving aproper emulsifier, and adding water for phase inversion emulsification.

In the above-mentioned methods [1]-[8], as the emulsifier or adispersant to be used in combination, conventionally known surfactants(s) and water-soluble polymers (t) can be used. Also, an assisting agentfor emulsification and dispersion, solvents (u) and plasticizers (v) maybe used in combination.

The surfactants (s) may include anionic surfactants (s-1), cationicsurfactants (s-2), amphoteric surfactants (s-3), and nonionicsurfactants (s-4). Two or more kinds of surfactants may be employed asthe surfactants (s). Practical examples of (s) may include thefollowings and those described in JP-A No. 2002-284881 as well.

As the anionic surfactants (s-1), carboxylic acids and their salts,sulfuric acid ester salts, salts of carboxymethylated compounds,sulfonic acid salts, and phosphoric acid esters can be employed.

Examples usable as the carboxylic acids and their salts may includesaturated and unsaturated fatty acids having 8 to 22 carbon atoms andtheir salts and practically the examples are capric acid, lauric acid,myristic acid, palmitic acid, stearic acid, arachidinic acid, behenicacid, oleic acid, linoleic acid, and ricinoleic acid as well as mixturesof higher fatty acids obtained by saponification of coconut oil, palmnuclei oil, rice bran oil, and beef tallow.

Their salts may include sodium salts, potassium salts, amine salts,ammonium salts, quaternary ammonium salts, and alkanolamine salts(monoethanolamine salts, diethanolamine salts, and triethanolaminesalts) of them.

Examples usable as the sulfuric acid ester salts may include higheralcohol sulfuric acid ester salts (sulfuric acid ester salts ofaliphatic alcohol having 8 to 18 carbon atoms), higher alkyl ethersulfuric acid ester salts (sulfuric acid ester salts of EO or PO 1 to 10mole adducts of aliphatic alcohol having 8 to 18 carbon atoms),sulfonated oils (natural unsaturated fats and oils or unsaturated waxeshaving 12 to 50 carbon atoms are reacted with sulfuric acid andneutralized), sulfonated fatty acid esters (lower alcohol (1 to 8 carbonatoms) esters of unsaturated fatty acids (6 to 40 carbon atoms) arereacted with sulfuric acid and neutralized), and sulfonated olefins(olefins having 12 to 18 carbon atoms are reacted with sulfuric acid andneutralized).

Their salts may include sodium salts, potassium salts, amine salts,ammonium salts, quaternary ammonium salts, and alkanolamine salts(monoethanolamine salts, diethanolamine salts, and triethanolaminesalts) of them.

Examples usable as the higher alcohol sulfuric acid ester salts mayinclude octyl alcohol sulfuric acid ester salts, decyl alcohol sulfuricacid ester salts, lauryl alcohol sulfuric acid ester salts, stearylalcohol sulfuric acid ester salts, and sulfuric acid ester salts ofalcohols synthesized using Ziegler catalyst (e.g., trade name: ALFOL1214, manufactured by CONDEA), sulfuric acid ester salts of alcoholssynthesized by oxo process (e.g., trade name: Dobanol 23, 25, 45 andDiadol 15-L, 115H, 135, manufactured by Mitsubishi Chemical IndustriesLtd., trade name: Tridecanol, manufactured by Kyowa Hakko Kogyo Co.,Ltd., trade name: Oxocol 1213, 1215, 1415, manufactured by NissanChemical Industries, Ltd.).

Examples usable as the higher alkyl ether sulfuric acid ester salts arelauryl alcohol EO 2 mole adduct sulfuric acid ester salts and octylalcohol EO 3 mole adduct sulfuric acid ester salts

Sulfonated oils may include sulfonated product salts of castor oil,peanut oil, olive oil, rapeseed oil, beef tallow, and sheep tallow.

Sulfonated fatty acid esters may include sulfonated product salts ofbutyl oleate and butyl ricinoleate.

Sulfonated olefins may include trade name: Teepol (manufactured byShell).

Examples usable as the carboxymethylated compound salts are salts ofcarboxymethylated aliphatic alcohols having 8 to 16 carbon atoms andsalts of carboxymethylated EO or PO 1 to 10 mole adducts of aliphaticalcohols having 8 to 16 carbon atoms.

Practical examples of carboxymethylated compound salts of aliphaticalcohols are octyl alcohol carboxymethylated sodium salt, lauryl alcoholcarboxymethylated sodium salt, carboxymethylated sodium salt of Dobanol23, and tridecanol carboxymethylated sodium salt.

Practical examples of salts of carboxymethylated EO 1 to 10 mole adductsof aliphatic alcohols are carboxymethylated octyl alcohol-EO 3 moleadduct sodium salt, carboxymethylated lauryl alcohol-EO 4 mole adductsodium salt, and carboxymethylated tridecanol-EO 5 mole adduct sodiumsalt.

Examples usable as the sulfonic acid salts may includealkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts,sulfosuccinic acid diester salts, α-olefinsulfonic acid salts, sulfonicacid salts of Igepon T type and other aromatic ring-containingcompounds.

Practical examples of alkylbenzenesulfonic acid salts may includedodecylbenzenesulfonic acid sodium salt.

Practical examples of alkylnaphthalenesulfonic acid salts may includedodecylnapthalenesulfonic acid sodium salt.

Practical examples of sulfosuccinic acid diester salts may includesulfosuccinic acid di-2-ethylhexyl ester sodium salt.

Practical examples of sulfosuccinic acid salts of aromaticring-containing compounds may include alkylated diphenyl ether mono- ordisulfonic acid salts and styrenated phenolsulfonic acid salts.

Examples usable as the phosphoric acid ester salts may include higheralcohol phosphoric acid ester salts and higher alcohol EO adductphosphoric acid ester salts.

Practical examples of higher alcohol phosphoric acid monoester salts arelauryl alcohol phosphoric acid ester disodium salt and lauryl alcoholphosphoric acid diester sodium salt.

Practical examples of higher alcohol EO adduct phosphoric acid estersalts may include oleyl alcohol EO 5 mole adduct phosphoric acidmonoester disodium salt.

The cationic surfactants (s-2) may include quaternary ammonium saltstype surfactants and amine salts type surfactants.

Examples usable as the quaternary ammonium salt type surfactants arethose obtained by reaction of tertiary amines having 3 to 40 carbonatoms with quaternarization agents (e.g., alkylation agents such asmethyl chloride, methyl bromide, ethyl chloride, benzyl chloride, anddimethylsulfuric acid and EO) and practical examples arelauryltrimethylammonium chloride, didecyldimethylammonium chloride,dioctyldimethylammonium bromide, stearyltrimethylammonium bromide,lauryldimethylbenzylammonium chloride (benzalconium chloride),cetylpyridinium chloride, polyoxyethylenetrimethylammonium chloride, andstearamidoethyldiethylmethylammonium methosulfate.

Examples usable as the amine salt type surfactants are those obtained byneutralization of primary to tertiary amines with inorganic acids (e.g.,hydrochloric acid, nitric acid, sulfuric acid, hydroiodic acid,phosphoric acid, and perchloric acid) or organic acids (e.g., aceticacid, formic acid, oxalic acid, lactic acid, gluconic acid, adipic acid,alkylphosphoric acid having 2 to 24 carbon atoms, malic acid, and citricacid).

Examples of the primary amine type surfactants may include inorganicacid salts or organic acid salts of aliphatic higher amines having 8 to40 carbon atoms (e.g., higher amines such as laurylamine, stearylamine,cetylamine, cured beef tallow amine, and rosin amine), and higher fattyacid (having 8 to 40 carbon atoms, e.g., stearic acid and oleic acid)salts of lower amines (having 2 to 6 carbon atoms).

Examples of the secondary amine type surfactants may include inorganicacid salts or organic acid salts of EO adducts of aliphatic amineshaving 4 to 40 carbon atoms.

Examples of the tertiary amine type surfactants may include inorganicacid salts or organic acid salts of aliphatic amines having 4 to 40carbon atoms (e.g., triethylamine, ethyldimethylamine, andN,N,N′,N′-tetramethylethylenediamine), aliphatic amine (having 2 to 40carbon atoms) EO (2 mole or higher) adducts, alicyclic amines having 6to 40 carbon atoms (e.g., N-methylpyrolidine, N-methylpiperidine,N-methylhexamethyleneimine, N-methylmorpholine, and1,8-diazabicyclo(5,4,0)-7-undecene), and nitrogen-containing heteroringaromatic amines having 5 to 30 carbon atoms (e.g.,4-dimethylaminopyridine, N-methylimidazole, and 4,4′-dipyridyl) andinorganic acid salts or organic acid salts of tertiary amines such astriethanolamine monostearate andstearamidoethyldiethylmethylethanolamine.

Examples usable as the amphoteric surfactants (s-3) may includecarboxylic acid salt type amphoteric surfactants, sulfuric acid estersalt type amphoteric surfactants, sulfonic acid salt type amphotericsurfactants, and phosphoric acid ester salt type amphoteric surfactants.

Examples of carboxylic acid salt type amphoteric surfactants areaminoacid type amphoteric surfactants, betaine type amphotericsurfactants, and imidazoline type amphoteric surfactants. The aminoacidtype amphoteric surfactants are amphoteric surfactants having aminogroup and carboxyl group in a molecule and, for example, compoundsdefined by the following formula (2) can be exemplified:[R—NH—(CH₂)_(n)—COO]_(m)M  (2)wherein R denotes monovalent hydrocarbon group; n denotes 1 or 2; mdenotes 1 or 2; M denotes hydrogen ion, an alkali metal ion, an alkalineearth metal ion, ammonium cation, amine cation, and alkanol aminecation.

Practical examples of the amphoteric surfactants defined by the formula(2) are alkyl (6 to 40 carbon atoms)-aminopropionic acid type amphotericsurfactants (stearylaminopropionic acid sodium salt andlaurylaminopropionic acid sodium salt); alkyl (4 to 24 carbonatoms)-aminoacetic acid type amphoteric surfactants (laurylaminoaceticacid sodium salt).

The betaine type amphoteric surfactants are amphoteric surfactants eachcomprising a quaternary ammonium salt type cationic portion and acarboxylic acid type anion portion in a molecule and examples of theamphoteric surfactants are alkyl (6 to 40 carbon atoms) dimethyl betaine(stearyl dimethylaminoacetic acid betaine and lauryl dimethylaminoaceticacid betaine), amidbetaine having 6 to 40 carbon atoms (copra oilamidpropylbetain) and alkyl (6 to 40 carbon atoms) dihydroxyalkylbetaine(lauryl dihydroxyethyl betaine).

The imidazoline type amphoteric surfactants are amphoteric surfactantseach comprising an imidazoline ring-containing cationic portion and acarboxylic acid type anion portion in a molecule and examples mayinclude 2-undecyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine.

Examples of other amphoteric surfactants are glycine type amphotericsurfactants such as sodium lauroyl glycine, sodium lauryldiaminoethylglycine, lauryldiaminoethyl glycine hydrochloride, anddioctyldiaminoethyl glycine hydrochloride; sulfobetaine type amphotericsurfactants such as pentadecylsulfotaurine, sulfonic acid salt typeamphoteric surfactants, and phosphoric acid ester salt type amphotericsurfactants.

The nonionic surfactants (s-4) may include AO adduct type nonionicsurfactants and polyhydric alcohol type nonionic surfactants.

The AO adduct type nonionic surfactants may be obtained by directlyadding AO (2 to 20 carbon atoms) to higher alcohols having 8 to 40carbon atoms, higher fatty acids having 8 to 40 carbon atoms, oralkylamines having 8 to 40 carbon atoms, or causing reaction of higherfatty acids with polyalkylene glycols obtained by AO addition toglycols, or adding AO to higher fatty acid amides.

AO includes EO, PO, and BO

Preferable examples among them are EO and random or block adducts of EOand PO.

The addition mole number of AO is preferably 10 to 50 mole and thosecontaining 50 to 100% of EO among AO are preferable.

The AO addition type nonionic surfactants may include oxyalkylene alkylethers (2 to 24 carbon atoms for alkylene and 8 to 40 carbon atoms foralkyl) (e.g., octyl alcohol EO 20 mole adduct, lauryl alcohol EO 20 moleadduct, stearyl alcohol EO 10 mole adduct, oleyl alcohol EO 5 moleadduct, and lauryl alcohol EO 10 mole-PO 20 mole block adduct);polyoxyalkylene higher fatty acid esters (2 to 24 carbon atoms foralkylene and 8 to 40 carbon atoms for higher fatty acid) (e.g., stearylacid EO 10 mole adduct and laurylic acid EO 10 mole adduct);polyoxyalkylene polyhydric alcohol higher fatty acid esters (2 to 24carbon atoms for alkylene, 3 to 40 carbon atoms for polyhydric alcohol,and 8 to 40 carbon atoms for higher fatty acid) (e.g., polyethyleneglycol (polymerization degree 20) lauric acid diester and polyethyleneglycol (polymerization degree 20) oleic acid diester); polyoxyalkylenealkyl phenyl ethers (2 to 24 carbon atoms for alkylene and 8 to 40carbon atoms for alkyl) (e.g., nonylphenol EO 4 mole adduct, nonylphenolEO 8 mole-PO 20 mole block adduct, octylphenol EO 10 mole adduct,bisphenol A-EO 10 mole adduct, and styrene-modified phenol EO 20 moleadduct); polyoxyalkylene alkyl aminoethers (2 to 24 carbon atoms foralkylene and 8 to 40 carbon atoms for alkyl) (e.g., laurylamine EO 10mole adduct and stearylamine EO 10 mole adduct); and polyoxyalkylenealkanolamides (2 to 24 carbon atoms for alkylene and 8 to 40 carbonatoms for amide (acyl portion)) (e.g., hydroxyethyl-lauric acid amide EO10 mole adduct and hydroxypropyloleic acid amide EO 20 mole adduct).

The polyhydric alcohol type nonionic surfactants may include polyhydricalcohol fatty acid esters, polyhydric alcohol fatty acid ester AOadducts, polyhydric alcohol alkyl ethers, and polyhydric alcohol alkylether AO adducts. The number of carbon atoms for the polyalcohol is 3 to24; the number of carbon atoms for the fatty acid is 8 to 40; and thenumber of carbon atoms for AO is 2 to 24.

Examples of the polyhydric alcohol fatty acid esters are pentaerythritolmonolaurate, pentaerythritol monooleate, sorbitane monolaurate,sorbitane monostearate, sorbitane dilaurate, sorbitane dioleate, andsucrose monostearate.

Examples of the polyhydric alcohol fatty acid ester AO adducts areethylene glycol monooleate EO 10 mole adduct, ethylene glycolmonostearate EO 20 mole adduct, trimethylolpropane stearate EO 20mole-PO 10 mole random adduct, sorbitane monolaurate EO 10 mole adduct,sorbitane distearate EO 20 mole adduct, and sorbitane dilaurate EO 12mole-PO 24 mole random adduct.

Examples of the polyhydric alcohol alkyl ethers are pentaerythritolmonobutyl ether, pentaerythritol monolauryl ether, sorbitane monomethylether, sorbitane monostearyl ether, methyl glycoside, and laurylglycoside.

Examples of polyhydric alcohol alkyl ether AO adducts are sorbitanemonostearyl ether EO 10 mole adduct, methyl glycoside EO 20 mole-PO 10mole random adduct, lauryl glycoside EO 10 mole adduct, and stearylglycoside EO 20 mole-PO 20 mole random adduct.

The water soluble polymer (t) may include cellulose type compounds(e.g., methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, and their saponified products); gelatin, starch, dextrin, gumarabic, chitin, chitosan, polyvinyl alcohol, polyvinylpyrrolidone,polyethylene glycol, polyethyleneimine, polyacrylamide, acrylic acid(salt)-containing polymers (e.g., poly(acrylic acid) sodium salt,poly(acrylic acid) potassium salt, poly(acrylic acid) ammonium salt,poly(acrylic acid) partially neutralized with sodium hydroxide, sodiumacrylate-acrylic acid ester copolymer); styrene-maleic anhydridecopolymer (partially) neutralized with sodium hydroxide, water-solublepolyurethanes (e.g., reaction products of polyethylene glycol andpolycaprolactone diol with polyisocyanate).

The solvent (u) to be used in the invention may be added to awater-based solvent or to a dispersion to be emulsified [in the oilphase containing the resin (b) or (b0)] based on the necessity at thetime of emulsification.

Practical examples of the solvent (u) are aromatic hydrocarbon solventssuch as toluene, xylene, ethylbenzene, and tetralin; aliphatic oralicyclic hydrocarbon solvents such as n-hexane, n-heptane, mineralspirit, and cyclohexane; halogen type solvents such as methyl chloride,methyl bromide, methyl iodide, methylene dichloride, perchloromethane,trichloroethylene, and perchloroethylene; ester or ester ether typesolvents such as ethyl acetate, butyl acetate, methoxybutyl acetate,methylcellosolve acetate, and ethylcellosolve acetate; ether typesolvents such as diethyl ether, tetrahydrofuran, dioxane, ethylcellosolve, butyl cellosolve, and propylene glycol monomethyl ether;ketone type solvents such as acetone, methyl ethyl ketone, methylisobutyl ketone, di-n-butylketone, and cyclohexanone; alcohol typesolvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol,isobutanol, tert-butanol, 2-ethylhexyl alcohol, and benzyl alcohol;amide type solvents such as dimethylformamide and dimethylacetamide;sulfoxide type solvents such as dimethyl sulfoxide; heterocycliccompound type solvents such as N-methylpyrrolidone; and mixed solventsof two or more of the above exemplified solvents.

The plasticizer (v) may be added to the water-based solvent or to adispersion to be emulsified [in the oil phase containing the resin (b)or (b0)] based on the necessity at the time of emulsification.

The plasticizer (v) is not necessarily limited and the following can beexemplified:

(v1) phthalic acid esters [e.g., dibutyl phthalate, dioctyl phthalate,butyl benzyl phthalate, and diisodecyl phthalate];

(v2) aliphatic di-basic acid esters [e.g., di-2-ethylhexyl adipate and2-ethylhexyl sebacate];

(v3) trimellitic acid esters [e.g., tri-2-ethylhexyl trimellitate andtrioctyl trimellitate];

(v4) phosphoric acid esters [e.g., triethyl phosphate, tri-2-ethylhexylphosphate, and tricresyl phosphate];

(v5) fatty acid esters [e.g., butyl oleate]; and

(v6) mixtures of two or more of the above exemplified esters.

The particle diameters of the resin particles (A) to be used in theinvention is generally smaller than those of the resin particles (B) tobe formed and in terms of the particle diameter evenness, the particlediameter ratio of [volume average particle diameter of resin particles(A)]/[volume average particle diameter of resin particles (B)] ispreferably in a range of 0.001 to 0.3. The lower limit of the particlediameter ratio is more preferably 0.003 and the upper limit is morepreferably 0.25. If the particle diameter ratio is larger than 0.3,since (A) cannot efficiently be attached on the surface of (B), theparticle distribution of (C) to be obtained tends to be widened.

The volume average particle diameter of the resin particles (A) isproperly adjusted within the above-mentioned particle diameter ratio soas to obtain resin particles (C) with desired particle diameters.

The volume average particle diameter of (A) is generally preferably0.0005 to 30 μm. The upper limit is more preferably 20 μm and even morepreferably 10 μm and the lower limit is preferably 0.01 μm, morepreferably 0.02 μm, and even more preferably 0.04 μm. However, in thecase the resin particles (C) with a volume average particle diameter of1 μm are to be obtained, it is preferably within a range of 0.0005 to0.3 μm and more preferably within a range of 0.001 to 0.2 μm; in thecase the resin particles (C) with a volume average particle diameter of10 μm are to be obtained, it is preferably within a range of 0.005 to 3μm and more preferably within a range of 0.05 to 2 μm; and in the casethe resin particles (C) with a volume average particle diameter of 100μm are to be obtained, it is preferably within a range of 0.05 to 30 μmand more preferably within a range of 0.1 to 20 μm.

The volume average particle diameter can be measured by laser typeparticle diameter distribution measurement apparatus LA-920(manufactured by Horiba Seisakusho), Multisizer III (manufactured byCoulter), and as an optical type, ELS-800 (manufactured by OtsukaElectronics Co., Ltd.) using Laser Doppler method. If the values of theparticle diameter measured by the respective measurement apparatuses aredifferent from one another, the measurement values of ELS-800 areemployed.

In this connection, since the above-mentioned particle diameter ratio iseasy to be attained, the volume average particle diameter of the resinparticles (B) described later is preferably in a range of 0.1 to 300 μm,more preferably in a range of 0.5 to 250 μm, and even more preferably ina range of 1 to 200 μm.

The resin (b) of the invention may be any resin if it is conventionallyknown resin and practical examples to be used as the resin are thoseexemplified for (a) and polyurethane resins mentioned below. Dependingon the uses and purposes, (b) may be selected properly.

Generally, preferable examples of the resin (b) are polyester resins,polyurethane resins, epoxy resins, vinyl resins and their combinations;more preferable examples are polyurethane resins and polyester resins;and even more preferable examples are polyurethane resins and polyesterresins containing 1,2-propylene glycol as a constituent unit.

The polyurethane resin may include addition polymerized products ofpolyisocyanates (15) and active hydrogen-containing compounds {water,polyols [abovementioned diols (11) [including diols (11a) containing afunctional group other than hydroxyl], and tri to octa or higher-hydricpolyols (12)], polycarboxylic acids [dicarboxylic acids (13) and tri tohexa or higher valent polycarboxylic acids (14)], polyester polyolsobtained by condensation polymerization of polyols and polycarboxylicacids, ring opening reaction polymers of lactones having 6 to 12 carbonatoms, polyamines (16), polythiols (17) and combinations thereof} aswell as amino-containing polyurethane resins obtained by causingreaction the terminal isocyanate groups of the prepolymers, whichobtained by reaction (15) with active hydrogen-containing compounds,with primary and/or secondary monoamines (18) in the equimolecularamount to that of the isocyanate groups of the prepolymers. The contentof carboxyl groups in the polyurethane resin is preferably 0.1 to 10%.

Polyisocyanates (15) may include aromatic polyisocyanates having 6 to 20carbon atoms (except the carbon in the NCO group, hereinafter the same);aliphatic polyisocyanates having 2 to 18 carbon atoms; alicyclicpolyisocyanates having 4 to 15 carbon atoms; aromatic aliphaticpolyisocyanates having 8 to 15 carbon atoms; and modified compounds ofthese polyisocyanates (e.g., modified compounds containing urethanegroup, carbodiimido group, allophanato group, urea group, biurat group,uretdione group, uretimine group, isocyanurate group, and oxazolidonegroup) and mixture of two or more of them.

Practical examples of the above-mentioned polyisocyanates are 1,3-and/or 1,4-phenylene diisocyanate, 2,4- and/or 2,6-tolylene diisocyanate(TDI), crude TDI, 2,4′- and/or 4,4′-diphenylmethanediisocyanate (MDI),crude MDI [e.g., crude diaminophenylmethane [condensation products offormaldehyde and aromatic amines (aniline) or their mixtures: phosgenecompounds of mixtures of diaminodiphenylmethane and a small amount(e.g., 5 to 20%) of tri- or higher functional polyamines]; polyallylpolyisocyanate (PAPI)], 1,5-naphthylenediisocyanate,4,4′,4″-triphenylmethane triisocyanate, m- andp-isocyanatophenylsulfonyl isocyanate.

Practical examples of the above-mentioned aliphatic polyisocyanates areethylene diisocyanate, tetramethylene diisocyanate, hexamethylenediisocyanate (HDI), dodecamethylene diisocyanate,1,6,11-undecatriisocyanate, 2,2,4-trimethylhexamethylene diisocyanate,lysine diisocyanate, 2,6-diisocyanatomethylcaproate,bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and2-isocyanatoethyl-2,6-diisocyanatohexanoate.

Practical examples of the above-mentioned alicyclic polyisocyanates areisophorone diisocyanate (IPDI), dicyclohexylmethae-4,4′-diisocyanate(hydrated MDI), cyclohexylene diisocyanate, methylcyclohexylenediisocyanate (hydrated TDI),bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, and 2,5- and/or2,6-norbornane diisocyanate.

Practical examples of the above-mentioned aromatic aliphaticpolyisocyanates are m- and/or p-xylylene diisocyanate (XDI),α,α,α′,α′-tetramethylxylylene diisocyanate (TMXDI).

Examples of the modified compounds of the above-mentionedpolyisocyanates are modified compounds having urethane group,carbodiimido group, allophanato group, urea group, biurat group,uretdione group, uretimine group, isocyanurate group, and oxazolidonegroup.

Practically, polyisocyanate modified compounds such as modified MDI(e.g., urethane-modified MDI, carbodiimido-modified MDI, andtrihydrocarbylphosphate-modified MDI) and urethane-modified MDI; andmixtures of two or more of these compounds [e.g., combination use ofmodified MDI and urethane-modified TDI (isocyanate-containingprepolymers)].

Those preferable among them are aromatic polyisocyanates having 6 to 15carbon atoms, aliphatic polyisocyanates having 4 to 12 carbon atoms, andalicyclic polyisocyanates having 4 to 15 carbon atoms and thoseparticularly preferable are TDI, MDI, HDI, hydrogenated MDI, and IPDI.

Examples of polyamines (16) are aliphatic polyamines (C2 to C18): [1]aliphatic polyamines {C2 to C6 alkylene diamine (e.g., ethylenediamine,propylenediamine, trimethylenediamine, tetramethylenediamine, andhexamethylenediamine), polyalkylene (C2 to C6) polyamines [e.g.,diethylenetriamine, iminobispropylamine, bis(hexamethylene)triamine,triethylenetetramine, tetraethylenepentamine, andpentaethylenehexamine]}; [2] these polyamines substituted with alkyl (C1to C4) or hydroxyalkyl (C2 to C4) [e.g. dialkyl (C1 to C3)aminopropylamine, trimethylhexmethylenediamine, aminoethylethanolamine,2,5-dimethyl-2,5-hexamethylenediamine, and methyliminobispropylamine];[3] alicyclic or heteroring-containing aliphatic polyamines [e.g.,3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane]; [4]aromatic group-containing aliphatic amines (C8 to C 15) (e.g.xylylenediamine, tetrachloro-p-xylylenediamine), alicyclic polyamines(C4 to C15) (e.g., 1,3-diaminocyclohexane, isophoronediamine,menthenediamine, and 4,4′-methylenedicyclohexanediamine (hydrogenatedmethylenedianiline)); and heterocyclic polyamines (C4 to C15) (e.g.,piperazine, N-aminoethylpiperazine, 1,4-diaminoethylpiperazine, and1,4-bis(2-amino-2-methylpropyl)piperazine): aromatic polyamines (C6 toC20): [1] un-substituted aromatic polyamines [e.g., 1,2-, 1,3-, and1,4-phenylenediamine, 2,4′- and 4,4′-diphenylmethanediamine, crudediphenylmethanediamine (polyphenylpolymethylenepolyamine),diaminodipenylsulfone, benzidine, thiodianiline,bis(3,4-diaminophenyl)sulfone, 2,6-diaminopyridine, m-aminobenzylamine,triphenylmethane-4,4′,4″-triamine, and naphthylenediamine]; aromaticpolyamines nuclear substituted with alkyl (C1 to C4 alkyl such asmethyl, ethyl, n- and iso-propyl, and butyl) [e.g., 2,4- and2,6-tolylenediamine, crude tolylenediamine, diethyltolylenediamine,4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-bis(o-toluidine),dianicsidine, diaminoditolylsulfone, 1,3-dimethyl-2,4-diaminobenzene,1,3-dimethyl-2,6-diaminobenzene, 1,4-diisopropyl-2,5-diaminobenzene,2,4-diaminomesitylene, 1-methyl-3,5-diethyl-2,4-diaminobenzene,2,3-dimethyl-1,4-diaminonaphthalene,2,6-dimethyl-1,5-diaminonaphthalene, 3,3′,5,5′-tetramethylbendizine,3,3′,5,5′-tetramethyl-4,4′-diaminodiphenylmethane,3,5-diethyl-3′-methyl-2′,4-diaminodiphenylmethane,3,3′-diethyl-2,2′-diaminodiphenylmethane,4,4′-diamino-3,3′-dimethyldiphenylmethane,3,3′,5,5′-tetraethyl-4,4′-diaminobenzophenone,3,3′,5,5′-tetraethyl-4,4′-diaminodiphenyl ether,3,3′,5,5′-tetraisopropyl-4,4′-diaminodiphenylsulfone] and mixtures ofthese isomers at various ratios; [3] aromatic polyamines having nuclearsubstituted electron attractive group (e.g., halogens such as Cl, Br, I,and F; alkoxy groups such as methoxy and ethoxy; and nitro groups)[e.g., methylene bis(o-chloroaniline), 4-chloro-o-phenylenediamine,2-chloro-1,4-phenylenediamine, 3-amino-4-chloroaniline,4-bromo-1,3-phenylenediamine, 2,5-dichloro-1,4-phenylenediamine,5-nitro-1,3-phenylenediamine, 3-dimethoxy-4-aminoaniline,4,4′-diamino-3,3′-dimethyl-5,5′-dibromodiphenylmethane,3,3′-dichlorobenzidine, 3,3′-dimethoxybenzidine,bis(4-amino-3-chlorophenyl) oxide, bis(4-amino-3-methoxyphenyl)propane,bis(4-amino-2-chlorophenyl)sulfone, bis(4-amino-3-methoxyphenyl)decane,bis(4-aminophenyl) sulfide, bis(4-aminophenyl) telluride,bis(4-aminophenyl) selenide, bis(4-amino-3-methoxyphenyl) disulfide,4,4′-methylenebis(2-iodoaniline), 4,4′-methylenebis(2-bromoaniline),4,4′-methylenebis(2-fluoroaniline), and 4-aminophenyl-2-chloroaniline];[4] aromatic polyamines having secondary amino groups [some or all of—NH₂ of the aromatic polyamines of [1] to [3] are substituted with—NH—R′ (R′ is a lower alkyl such as methyl and ethyl)] [e.g.,4,4′-di(methylamino)diphenylmethane and1-methyl-2-methylamino-4-aminobenzene], polyamidopolyamines [e.g., lowmolecular weight polyamidopolyamines obtained by condensation ofdicarboxylic acids (e.g., dimer acids) and excess amounts (2 mole ormore per 1 mole of acids) of polyamines (the above-mentionedalkylenediamines and polyalkylene polyamines); and polyether polyamines(e.g., cyanoethylated polyether polyol (polyalkylene glycol) hydrides).

Examples of polythiols (17) may include alkane dithiols having 2 to 36carbon atoms (e.g., ethylenedithiol, 1,4-butanedithiol, and1,6-hexanedithiol).

Examples of primary and/or secondary monoamines (18) may includealkylamines having 2 to 24 carbon atoms (e.g., ethylamine, n-butylamine,and isobutylamine).

The Mn, melting point, Ts, and sp value of the resin (b) may properly beadjusted in preferable ranges, respectively, in accordance with theuses.

The sp value of the resin (b) is preferable to satisfy the sp valuedifference from that of the resin (a) within a range defined in thesecond invention and it is generally within a range of 7 to 18,preferably within a range of 8 to 14, and more preferably within a rangeof 9 to 14.

For example, in the case the resin particles (C) and resin particles (B)are used for a resin for slush molding or a powder coating, Mn of (b) isgenerally in a range of 2,000 to 500,000 and preferably in a range of4,000 to 200,000. The melting point (measured by DSC, hereinafter, themelting point is a value measured by DSC) of (b) is generally in a rangeof 0° C. to 200° C. and preferably 35° C. to 150° C. Tg of (b) isgenerally in a range of −60° C. to 100° C. and preferably −30° C. to 60°C.

In the case of using (b) for a spacer for producing electronic parts orapparatus such as a liquid crystal display and a standard particle forelectron measurement instruments, Mn of (b) is generally in a range of20,000 to 10,000,000 and preferably 40,000 to 2,000,000. The meltingpoint (measured by DSC, hereinafter, the melting point is a valuemeasured by DSC) of (b) is generally in a range of 40° C. to 300° C. andpreferably 70° C. to 250° C. Tg of (b) is generally in a range of −0° C.to 250° C. and preferably 50° C. to 200° C.

In the case of using (b) for a toner to be used for electrophotograph,electrostatic recording, and electrostatic printing, Mn of (b) isgenerally in a range of 1,000 to 5,000,000 and preferably 2,000 to500,000. The melting point (measured by DSC, hereinafter, the meltingpoint is a value measured by DSC) of (b) is generally in a range of 20°C. to 300° C. and preferably 80° C. to 250° C. Tg of (b) is generally ina range of 20° C. to 200° C. and preferably 40° C. to 200° C. The spvalue of (b) is generally in a range of 8 to 16 and preferably 9 to 14.

In the first invention, the attraction power of the resin (a) composingthe core layer (Q) to the resin (b) composing the shell layer (P) can becontrolled by the following methods.

[1]: If the resin (a) and the resin (b) are made to have mutuallyreversed electric charge, the attraction power is generated and in thiscase, if the electric charge of the resin (a) and the resin (b) are madehigher, the attraction power becomes more strong and the shell resin (a)is prevented from peeling off the core resin (b).[2]: If both of the resin (a) and the resin (b) are made to haveelectric charge with the mutually same polarity (both are made positiveor both are made negative), the attraction power of the shell resin (a)to the core resin (b) is weakened to make formation of the core-shellform difficult and even if it is formed once, the shell resin (a)sometimes peels off the core resin (b). In this case, generally if thesurfactant (s) and/or the water-soluble polymer (t) [particularly havingopposed electric charge to that of the resin particles (A) and the resinparticles (B)] is used, the attraction power is provided and therefore,it becomes easy to form the core-shell form or the shell resin (a) isprevented from peeling off the core resin (b).[3]: In the case of producing the water-based dispersion (W) and thecoating agent (W′), which is a water-based liquid, if the resin (a) is aresin having an acidic functional group such as carboxyl group,phosphoric acid group, and sulfonic acid group (generally it ispreferable that the molecular weight per one acidic functional group is1,000 or lower), the attraction power becomes stronger as the pH of thewater-based solvent is lower. On the contrary, the attraction powerbecomes weaker as the pH of the water-based solvent is higher.[4]: In the case of producing the water-based dispersion (W) or thecoating agent (W′), which is a water-based liquid, if the resin (a) is aresin having a basic functional group such as primary amino group,secondary amino group, tertiary amino group, and quaternary ammoniumgroup (generally it is preferable that the molecular weight per onebasic functional group is 1,000 or lower), the attraction power becomesstronger as the pH of the water-based solvent is higher. On thecontrary, the attraction power becomes weaker as the pH of thewater-based solvent is lower.[5]: The attraction power becomes stronger if the sp value difference(Δsp) of the resin (a) and the resin (b) is made narrower. However, ifthe Δsp value is made too narrow, sometimes the resin (a) and the resin(b) are dissolved to make it impossible to form core-shell typeparticles.

In the above-mentioned production methods (I) to (III), in the case theresin particles (C2) are produced in a water-based solvent, the resinparticles (C2) are obtained by removing the water-based solvent from thewater-based dispersion of the resin particles. A method for removing thewater-based solvent may be as follows

[1]: A method of drying the water-based resin dispersion in reducedpressure or normal pressure.

[2]: A method of solid-liquid separating the dispersion by a centrifugalseparator, Sparkler filter, or a filter press and drying the obtainedpowder.

[3]: A method of freezing the water-based resin dispersion and thendrying the dispersion (so-called freeze-drying).

In the above [1] and [2], at the time of drying the obtained powder,conventionally known facilities such as a fluidized layer type dryingapparatus, a pressure reduction drying apparatus, and an air circulationdrying apparatus may be employed.

Further, if necessary, an air blowing classifier may be employed forclassification and adjustment of particle size distribution.

The shape of the resin particles (C2) of the first invention may becontrolled by the following methods in accordance with theabove-mentioned production methods.

(1) In the Case of Production Method (I)

The particle shape and the particle surface property can be controlledby controlling sp value difference of the resin particles (A) and theresin particles (B) and the molecular weight of the resin particles (A).If the sp value difference is narrow, particles with smooth surface andirregular shape are easily obtained and if the sp value difference iswide, particles with rough surface and spherical shape are easilyobtained. Also, if the molecular weight of (A) is high, particles withrough surface are easily obtained and if the molecular weight is low,particles with smooth surface are easily obtained. However, if the spvalue difference of (A) and (B) is too narrow or too wide, thegranulation becomes difficult. Also, if the molecular weight of theresin particles (A) is too small, the granulation becomes difficult.Accordingly, the sp value difference of (A) and (B) is preferably in arange of 0.01 to 5.0, more preferably in a range of 0.1 to 3.0, and evenmore preferably in a range of 0.2 to 2.0. Further, the weight averagemolecular weight of the resin particles (A) is preferably in a range of100 to 1,000,000, more preferably in a range of 1000 to 500,000,furthermore preferably in a range of 2000 to 200,000, and even morepreferably in a range of 3000 to 100,000.

(2) In the Case of Production Method (II) and Production Method (III)

In both production methods, the shape of the resin particles (B) to beproduced previously considerably affect the particle shape and the resinparticles (C2) are formed in approximately same shape as that of theresin particles (B). In the case (B) have irregular shape, if a higheramount of the coating agent (W′) is used in the production method (II),the shape becomes spherical. Further, in the production method (III), ifheating treatment is carried out at a temperature higher than Tg of (B),(C2) become spherical.

In terms of the particle diameter evenness, powder flowability, andstorage stability of the resin particles (C2), the surface of the corelayer (Q) is covered with the shell layer (P) preferably at 70% orhigher, more preferably 80% or higher, furthermore preferably 90% orhigher, and even more preferably 95% or higher. The surface coverage iscalculated according to the following equation from the results of imageanalysis of an image obtained by a scanning electron microscope (SEM).Surface coverage (%)=[surface area of (P)−covered portion/surface areaof (P)−covered portion+Q−exposed portion]×100.

In the second, third, fourth, eighth, and tenth inventions and in theabove-mentioned production method (I) for obtaining the resin particlesof the first invention, the attraction power of the resin particles (A)to the resin particles (B) can be controlled by the following methods.

[1]: At the time of producing the water-based dispersion (W), if theresin particles (A) and the resin particles (B) are made to havemutually reversed electric charge, the attraction power is generated andin this case, if the electric charge of the resin particles (A) and theresin particles (B) are respectively made higher, the attraction powerbecomes more strong and the coverage of particles (A) on the resinparticles (B) become higher.[2]: At the time of producing the water-based dispersion (W), if both ofthe resin particles (A) and the resin particles (B) are made to haveelectric charge with the mutually same polarity (both are made positiveor both are made negative), the coverage tends to be decreased. In thiscase, generally if the surfactant (s) and/or the water-soluble polymer(t) [particularly having opposed electric charge to that of the resinparticles (A) and the resin particles (B)] is used, the coverage isincreased.[3]: At the time of producing the water-based dispersion (W), if theresin (a) is a resin having an acidic functional group such as carboxylgroup, phosphoric acid group, and sulfonic acid group (generally it ispreferable that the molecular weight per one acidic functional group is1,000 or lower), the coverage is increased more as the pH of thewater-based solvent is lower. On the contrary, the coverage is decreasedas the pH is higher.[4]: At the time of producing the water-based dispersion (W), if theresin (a) is a resin having a basic functional group such as primaryamino group, secondary amino group, tertiary amino group, and quaternaryammonium group (generally it is preferable that the molecular weight perone basic functional group is 1,000 or lower), the coverage is increasedmore as the pH of the water-based solvent is higher. On the contrary,the coverage is decreased as the pH is lower.[5]: The coverage is increased more if the sp value difference (Δsp) ofthe resin particles (A) and the resin particles (B) is made narrower.

In the second, third, fourth, eighth, and tenth inventions and in theabove-mentioned production method (I) for obtaining the resin particlesof the first invention, the water-based resin dispersion (X1) isobtained as a water-based dispersion of resin particles (C1) each havinga structure composed of (A) adhering to the surfaces of (B) bydispersing the resin (b) or it solvent solution in the water-baseddispersion of the resin particles (A) comprising the resin (a) andforming the resin particles (B) comprising the resin (b) in thewater-based dispersion of (A).

Also, the water-based resin dispersion (X1) is obtained as a water-baseddispersion of resin particles (C1) each having a structure composed of(A) adhering to the surfaces of (B) by dispersing the resin precursor(b0) of the resin (b) or it solvent solution in the water-baseddispersion of the resin particles (A) comprising the resin (a), causingreaction of (b0), and forming the resin particles (B) comprising theresin (b) in the water-based dispersion of (A).

In the case of dispersing the resin (b) or its solvent solution,alternatively the precursor (b0) of the resin (b) or its solventsolution, a dispersing apparatus may be used.

The dispersing apparatus to be used in the invention is not particularlylimited if it is commonly commercialized as an emulsifier or a disperserand examples usable as the apparatus are a batch type emulsifier such asa Homogenizer (manufactured by IKA), Polytron (manufactured byKinematica), and TK Auto-Homo-Mixer (manufactured by Tokushu Kika KogyoCo., Ltd.); a continuous type emulsifier such as Ebara Milder(manufactured by Ebara Corp.), TK Filmix, TK Pipeline Homomixer(manufactured by Tokushu Kika Kogyo Co., Ltd.), Colloid Mill(manufactured by Shinko Pantec Co., Ltd.), Slasher, Trigonal wetpulverizer (manufactured by Mitsui-Miike Kakoki), Capitron (manufacturedby Eurotec), and Fine Flow Mill (manufactured by Taiheiyo Kiko); a highpressure emulsifier such as Micro Fluidizer (manufactured by MizuhoKogyo), Nanomizer (manufactured by Nanomizer), and APV Goulin(manufactured by Goulin); a film emulsifier such as Film Emulsifier(manufactured by Reika Kogyo); a vibration type emulsifier such asVibromixer (manufactured by Reika Kogyo); and an ultrasonic emulsifiersuch as Ultrasonic Homogenizer (Branson). Preferable apparatuses amongthem in terms of the evenness of the particle diameter are APV Goulin,Homogenizer, TK Auto Homomixer, Ebara Milder, TK Filmix, and TK PipelineHomomixer.

At the time of dispersing the resin (b) in the water-based dispersion(W) of resin particles (A), the resin (b) is preferable to be a liquid.If the resin (b) is solid at a normal temperature, the resin may bedispersed in a liquid phase at a high temperature equal to or higherthan the melting point or a solvent solution of (b) may be used.

The viscosity of the resin (b) or its solvent solution, alternativelythe precursor (b0) of the resin or its solvent solution is generally 10to 50,000 mPa·s (measured by B type viscometer) and preferably 100 to10,000 mPa·s in terms of the evenness of the particle diameter.

The temperature at the time of dispersion is generally 0 to 150° C.(under pressure) and preferably 5 to 98° C. In the case the viscosity ofthe dispersion is high, it is preferable to carry out emulsification anddispersion after the viscosity is lowered to the above-mentionedpreferable range by heating to a high temperature.

In the case of using a solvent solution of the resin (b) or theprecursor (b0), the solvent to be used is not particularly limited if itcan dissolve the resin (b) therein at a normal temperature or underheating. Practically, the same solvents as those exemplified as thesolvent (u) may be employed. Although it depends on the type of theresin (b), preferable examples are those which give the sp valuedifference from that of the resin (b) 3 or lower. In terms of theparticle diameter evenness of the resin particles (C), it is preferablefor the solvent to dissolve the resin (b) therein but to be difficult todissolve or swell the resin particles (A) comprising the resin (a).

The precursor (b0) of the resin (b) is not particularly limited if itbecomes the resin (b) by chemical reaction and in the case the resin (b)is a vinyl resin, (b0) may be the above-mentioned vinyl monomers(possible to be used alone or in form of a mixture) and their solventsolution and in the case the resin (b) is a condensed type resin (e.g.,polyurethane resins, epoxy resins, and polyester resins), (b0) may be acombination of a prepolymers (α) having a reactive group and a curingagent (β) and

In the case vinyl monomers are used as the precursor (b0), a method ofcausing the precursor (b0) to reaction to become the resin (b) may be amethod of dispersing and suspending an oil phase containing anoil-soluble initiator, the monomers, and if necessary the solvent (u) inwater in the presence of the water-soluble polymer (t) and carrying outradical polymerization reaction by heating (so-called suspensionpolymerization method) and a method of emulsifying an oil phasecontaining the monomers, and if necessary the solvent (u) in awater-based dispersion of the resin particles (A) containing anemulsifier (examples are same as those exemplified for the surfactant(s)) and a water-soluble initiator and then carrying out radicalpolymerization reaction by heating (so-called emulsionpolymerization-method).

Peroxide polymerization initiator (I), azo polymerization initiator (II)may be used as the oil-soluble and water-soluble polymerizationinitiators. Further, redox type polymerization initiator (III) may beproduced by combination use of peroxide polymerization initiator (I) andreducing agent. And two or more of (I) to (III) may be used incombination.

(I) Peroxide Polymerization Initiator

(I-1) Oil-soluble peroxide polymerization initiators:acetylcyclohexylsulfonyl peroxide, isobutyryl peroxide, diisopropylperoxydicarbonate, di-2-ethylhexyl peroxydicarbonate,2,4-dichlorobenzoyl peroxide, tert-butyl peroxypivalate, octanoylperoxide, lauroyl peroxide, propionyl peroxide, succinic acid peroxide,acetyl peroxide, tert-butyl peroxy-2-ethylhexanoate, benzoyl peroxide,p-chlorobenzoyl peroxide, tert-butyl peroxyisobutyrate, tert-butylperoxymaleic acid, tert-butyl peroxylaurate, cyclohexanone peroxide,tert-butyl peroxyisopropylcarbonate, tert-butyl peroxyacetate,tert-butyl peroxybenzoate, diisobutyl diperoxyphthalate, methyl ethylketone peroxide, dicumyl peroxide, tert-butylcumyl peroxide, tert-butylhydroperoxide, di-tert-butyl peroxide, diisopropylbenzene hydroperoxide,p-methane hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, andcumene peroxide.

(I-2) Water-soluble peroxide polymerization initiators: hydrogenperoxide, peracetic acid, ammonium persulfate, and sodium persulfate.

(II) Azo Polymerization Initiator

(II-1) Oil-soluble azo polymerization initiator:2,2′-azobisisobutyronitrile, 1,1′-azobiscyclohexane-1-carbonitrile,2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile),2,2′-azobis(2,4-dimethylvaleronitrile),dimethyl-2,2′-azobis(2-methylpropionate),1,1′-azobis(1-acetoxy-1-phenylethane), and2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile).

(II-2) Water-soluble azo polymerization initiator: azobisamidinopropanesalt, azobiscyanovaleric acid (salt), and2,2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]

(III) Redox Polymerization Initiator

(III-1) non-aqueous redox polymerization initiator: combination use ofoil-soluble peroxides such as hydroperoxide, dialkyl peroxide, anddiacyl peroxide and oil-soluble reducing agents such as tertiaryamines,naphthenicacidsalts, mercaptans, organometal compounds (e.g.,triethylaluminum, triethylboron, and diethylzinc)

(III-2) water-based redox polymerization initiator: combination use ofwater-soluble peroxides such as persulfates, hydrogen peroxide,hydroperoxides and water-soluble inorganic or organic reducing agents(e.g., ferrous salts, sodium hydrogen sulfite, alcohols, andpolyamines).

As the precursor (b0), a combination of the reactive group-containingprepolymers (α) and the curing agent (β) may be employed. Herein,“reactive group” means a group reactive with the curing agent (β). Inthis case, a method for forming the resin (b) by causing reaction of theprecursor (b0) may include a method of dispersing an oil phasecontaining the reactive group-containing prepolymers (α), the curingagent (β), and if necessary the solvent (u) in the water-baseddispersion of the resin particles (A), causing reaction of the reactivegroup-containing prepolymers (α) and the curing agent (β), and therebyforming the resin particles (B) comprising the resin (b); a method ofdispersing the reactive group-containing prepolymers (α) or its solventsolution in the water-based dispersion of the resin particles (A),adding the water-soluble curing agent (β) to the mixture, causingreaction, and thereby forming the resin particles (B) comprising theresin (b); and in the case the reactive group-containing prepolymers (α)is cured by reaction with water, a method of dispersing the reactivegroup-containing prepolymers (α) or its solvent solution in thewater-based dispersion of the resin particles (A), causing reaction withwater, and thereby forming the resin particles (B) comprising the resin(b).

Combinations of reactive groups of the reactive group-containingprepolymers (α) and the curing agent (β) may include the following [1]and [2].

[1]: A combination of a functional group (α1) reactive with an activehydrogen compound as the reactive group of the reactive group-containingprepolymers (α) and an active hydrogen-containing compound (β1) as thecuring agent (β)

[2]: A combination of an active hydrogen-containing group (α2) as thereactive group of the reactive group-containing prepolymers (α) and acompound (β2) reactive with the active hydrogen-containing group as thecuring agent (β).

In terms of the reaction ratio in water, [1] is more preferable betweenthem.

In the combination [1], functional group (α1) reactive with an activehydrogen compound may include an isocyanate group (α1a), a blockedisocyanate group (α1b), an epoxy group (α1c), an acid anhydride group(α1d), and a acid halide group (α1e). Preferable examples among them are(α1a), (α1b), and (α1c) and particularly preferable examples are (α1a)and (α1b).

The blocked isocyanate (α1b) means isocyanate blocked by a blockingagent.

The above-mentioned blocking agent may include oximes [e.g., acetoxime,methylisobutyl ketoxime, diethyl ketoxime, cyclopentanone oxime,cyclohexanone oxime, and methyl ethyl ketoxime]; lactams [e.g.,γ-butyrolactam, ε-caprolactam, and γ-valerolactam]; aliphatic alcoholshaving 1 to 20 carbon atoms [e.g., ethanol, methanol, and octanol];phenols [e.g., phenol, m-cresol, xylenol, and nonylphenol]; activemethylene compounds [e.g., acetylacetone, ethyl malonate, and ethylacetoacetate]; basic nitrogen-containing compound [e.g.,N,N-diethylhydroxylamine, 2-hydroxypyridine, pyridine N-oxide, and2-mercaptopyridine]; and mixtures of two or more of the aboveexemplified compounds.

Oximes are preferable among them and methyl ethyl ketoxime isparticularly preferable.

The skeleton structure of the reactive group-containing prepolymers (α)may be polyethers (αw), polyesters (αx), epoxy resins (αy), andpolyurethanes (αz). (αx), (αy), and (αz) are preferable among them and(αx) and (αz) are particularly preferable.

Examples of the polyethers (αw) are polyethylene oxide, polypropyleneoxide, polybutylene oxide, and polytetramethylene oxide.

Examples of the polyesters (αx) are condensation polymerization productsof diols (11) and dicarboxylic acids (13) and polylactone (ring-openingpolymers of ε-caprolactone).

Examples of the epoxy resins (αy) are addition condensation products ofbisphenols [e.g., bisphenol A, bisphenol F, and bisphenol S] andepichlorohydrin.

Examples of the polyurethanes (αz) are addition polymerization productsof diols (11) and polyisocyanates (15) and addition polymerizationproducts of polyesters (αx) and polyisocyanates (15).

A method for introducing a reactive group into the polyesters (αx),epoxy resins (αy), and polyurethanes (αz) are as follows.

[1]: A method for leaving functional groups of a constituent componentin terminals by using an excess amount of one constituent componentamong two or more constituent components.

[2]: A method for leaving functional groups of a constituent componentin terminals by using an excess amount of one constituent componentamong two or more constituent components and causing reaction of theremaining functional groups with a compound having a functional groupand a reactive group reactive with the remaining functional groups.

In the above-mentioned method [1], hydroxyl-containing polyesterprepolymers, carboxyl-containing polyester prepolymers, acidhalide-containing polyester prepolymers, hydroxyl-containing epoxyprepolymers, epoxy group-containing epoxy prepolymers,hydroxyl-containing polyurethane prepolymers, and isocyanatogroup-containing polyurethane prepolymers are obtained.

With respect to the ratio of the constituent components, in the case ofthe hydroxyl-containing polyester prepolymers, the ratio of a polyol (1)and a polycarboxylic acid (2) on the basis of the equivalent ratio[OH]/[COOH] of the hydroxyl [OH] and the carboxyl [COOH] is generally ina range of 2/1 to 1/1, preferably in a range of 1.5/1 to 1/1, and morepreferably in a range of 1.3/1 to 1.02/1. Also in the case of otherskeleton structures and prepolymers having different terminal groups,the ratio is same although the constituent components are changed.

In the above-mentioned method [2], polyisocyanate is reacted on theprepolymers obtained by the above-mentioned method [1] to obtainisocyanate-containing prepolymers: blocked polyisocyanate is reacted toobtain blocked isocyanate group-containing prepolymers: polyepoxide isreacted to obtain epoxy group-containing prepolymers: and polyacidanhydride is reacted to obtain acid anhydride group-containingprepolymers.

With respect to the use amount of the compounds having a functionalgroup and a reactive group, in the case polyisocyanate is reacted withthe hydroxyl-containing polyesters to obtain the isocyanatogroup-containing polyester prepolymers, the ratio of the polyisocyanateand a hydroxyl-containing polyester on the basis of the equivalent ratio[NCO]/[OH] of the isocyanate group [NCO] and hydroxyl [OH] of thehydroxyl-containing polyester is generally in a range of 5/1 to 1/1,preferably in a range of 4/1 to 1.2/1, and more preferably in a range of2.5/1 to 1.5/1. Also in the case of other skeleton structures andprepolymers having different terminal groups, the ratio is same althoughthe constituent components are changed.

The reactive groups contained in one molecule of the reactivegroup-containing prepolymers (α) is generally one or higher, morepreferably 1.5 to 3, and more preferably 1.8 to 2.5 in average. Themolecular weight of a cured product to be obtained by reaction with thecuring agent (β) is increased by adjusting it in the above-mentionedrange.

The Mn of the reactive group-containing prepolymers (α) is generally 500to 30,000, preferably 1,000 to 20,000, and more preferably 2,000 to10,000.

The weight average molecular weight of the reactive group-containingprepolymers (α) is 1,000 to 50,000, preferably 2,000 to 40,000, and morepreferably 4,000 to 20,000.

The viscosity of the reactive group-containing prepolymers (α) at 100°C. is generally 2000 poise or lower and preferably 1,000 poise or lower.It is preferable to adjust the viscosity to be 2,000 poise or lowersince the resin particles (C) with a sharp particle size distributionwith a small amount of the solvent can be obtained.

The active hydrogen group-containing compound (β1) may includepolyamines (β1a) optically blocked with dissociable compounds, polyols(β1b), polymercaptans (β1c), and water (β1d). (β1a), (β1b) and (β1d) arepreferable among them and (β1a) and (β1d) are more preferable andblocked polyamines and (β1d) are even more preferable.

Examples of (β1a) are same as those exemplified as the polyamines (16).Preferable examples of (β1a) are 4,4′-diaminophenylmethane,xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine,triethylenetetramine and their mixtures.

Examples of (β1a) in the case (β1a) denote polyamines blocked withdissociable compounds are ketimines obtained from the above-mentionedpolyamines and ketones having 3 to 8 carbon atoms (e.g., acetone, methylethyl ketone, and methyl isobutyl ketone); and aldimine compoundsobtained from aldehyde compounds having 2 to 8 carbon atoms (e.g.,formaldehyde and acetaldehyde), enamine compounds, and oxazolidonecompounds.

Examples of polyols (β1b) are same as those exemplified above as diols(11) and polyols (12). Diols (11) alone or mixtures of diols (11) andslight amounts of polyols (12) are preferable.

Examples of polymercaptans (β1c) are ethylenedithiol, 1,4-butanedithiol,and 1,6-hexanedithiol.

If necessary, a reaction stopping agent (βs) may be used in combinationwith the active hydrogen group-containing compound (β1). Use of thereaction stopping agent (β1) in combination at a certain constant ratiomakes it possible to adjust (b) to have a prescribed molecular weight.

Examples of the reaction stopping agent (βs) are monoamines (e.g.,diethylamine, dibutylamine, butylamine, laurylamine, monoethanolamine,and diethanolamine); blocked monoamines (e.g., ketimine compounds);monool (e.g., methanol, ethanol, isopropanol, butanol, and phenol);monomercaptans (e.g., butylmercaptan and laurylmercaptan);monoisocyanates (lauryl isocyanate and phenyl isocyanate); andmonoepoxides (e.g., butyl glycidyl ether).

The active hydrogen-containing groups (α2) of the reactivegroup-containing prepolymers (α) in the above-mentioned combination [2]may include amino groups (α2a), hydroxyl groups (alcohol type hydroxylgroup and phenolic type hydroxyl group) (α2b), mercapto groups (α2c),carboxyl groups (α2d), and organic groups (α2e) blocked with dissociablecompounds. The compounds (α2a), (α2b) and organic groups (α2e) withamino group blocked by dissociable compounds are preferable among themand (α2b) are particularly preferable.

The organic groups with amino group blocked by dissociable compounds arethose same as the compounds exemplified for the above-mentioned (β1a).

Examples of compounds (β2) reactive with the active hydrogen-containinggroups are polyisocyanates (β2a), polyepoxides (β2b), polycarboxylicacids (β2c), polyacid anhydrides (β2d), and polyacid halides (β2e).Preferable compounds among them are (β2a) and (β2b) and more preferablecompounds are (β2a).

Examples of the polyisocyanates (β2a) are same as those exemplified asthe polyisocyanates (15) and preferable ones are also same.

Examples of the polyepoxides (β2b) are same as those exemplified as thepolyepoxides (18) and preferable ones are also same.

Examples of the polycarboxylic acids (β2c) are dicarboxylic acids(β2c-1) and tri- or higher valent polycarboxylic acids (β2c-2) and(β2c-1) alone and mixtures of (β2c-1) and small amounts of (β2c-2) arepreferable.

Examples of the dicarboxylic acids (β2c-1) are same as theabove-mentioned dicarboxylic acids (13) and polycarboxylic acids aresame as the above-mentioned polycarboxylic acids (5) and preferable onesare also same.

Examples of polycarboxylic anhydrides (β2d) may include pyromelliticacid anhydride.

Examples of the polyacid halides (β2e) are the acid halides of theabove-mentioned (β2c) (e.g., acid chloride, acid bromide, and acidiodide).

Further, based on the necessity, the reaction stopping agent (βs) may beused in combination with (β2).

The ratio of the curing agent (β) on the basis of the equivalent ratio[α]/[β] of the equivalent amount [α] of the reactive groups in thereactive group-containing prepolymers (α) and that of the activehydrogen-containing groups [β] of the curing agent (β) is preferably ina range from 1/2 to 2/1, more preferably in a range from 1.5/1 to 1/1.5,and even more preferably in a range from 1.2/1 to 1/1.2. In the case thecuring agent (β) is water (β1d), water is regarded as a divalent activehydrogen compound.

The resin (b) obtained by reaction of the precursor (b0) comprising thereactive group-containing prepolymers (α) and the curing agent (β) inthe water-based solvent becomes a constituent component for the resinparticles (B) and the resin particles (C). The weight average molecularweight of the resin (b) formed by reaction of the reactivegroup-containing prepolymers (α) and the curing agent (β) is generally3,000 or higher, preferably 3,000 to 10,000,000, and more preferably5,000 to 1,000,000.

At the time of reaction of the reactive group-containing prepolymers (α)and the curing agent (β) in the water-based solvent, it is allowed toadd a polymer (so-called dead polymer) which does not react with thereactive group-containing prepolymers (α) and the curing agent (β). Inthis case, (b) becomes a mixture of the resin obtained by reaction ofthe reactive group-containing prepolymers (α) and the curing agent (β)in the water-based solvent and the resin which is not reacted.

The use amount of the water-based solvent (W) to 100 parts of the resin(b) or the precursor (b0) is preferably in a range of 50 to 2,000 partsby weight and more preferably in a range of 100 to 1,000 parts byweight. If it is 50 parts by weight or more, the dispersion state of (b)is good and if it is 2,000 parts by weight or less, it is economical.

In the inventions, use of the resins (a) and (b) satisfying that thepoint (K, H) is within the specified range in the second invention oruse of the resin (a) having the physical properties such as (Ts) and(Tg) of the third invention, for example, particularly in the case ofusing a solvent (particularly the following preferable solvents)solution of (b) or (b0), makes it possible to dissolve the resinparticles (A) in the solvent and form a film-like shape and to obtainthe water-based dispersion (X2) of the resin particles (C21) comprising(B) bearing coating of (A) in many cases only by using the solvent forthe water-based resin dispersion (X1) at a ratio preferably in a rangeof 10 to 50% (more preferably in a range of 20 to 40%) and thendesolvating the solvent of the water-based resin dispersion (X1) to 1%or lower (particularly 0.5% or lower) at 40° C. or lower. However, inthe case the coating of (A) is not formed, or even in the case a coatingis formed using at least a portion of (A), if the following process iscarried out to make the smoothness of the coating on the surfaces of theresin particles (C) better, the water-based resin dispersion (X2) of theresin particles (C21) each comprising the core layer (Q) composed of (B)and a surface-smoothed coating [the shell layer (P)] of (A) on at leasta portion or preferably on the entire face of the surface of the corelayer (Q) can be obtained and (C21) to be obtained from the dispersionare excellent in the storage stability and therefore, it is preferable.

The above-mentioned method may include a method of dissolving (A)adhering to (B) in a solvent and a method of heating the water-basedresin dispersion (X1) and thereby melting (A) and forming a film andthese methods may be combined.

The solvent to be used for dissolving the resin particles (A) thereinand forming a film may be added to (X1) at the time of film formation,however it is preferable that the solvent solution of the resin (b) orthe precursor (b0) is used as a raw material of (X1) and the solvent isnot removed immediately after formation of the resin particles (B) tothereby make use of the solvent for the purpose since the solvent iscontained in (B) and dissolution of (A) is therefore easy andagglomeration of the resin preferably becomes difficult.

Those having high affinity to (b) are preferable as the solvent andpractical examples are same as those exemplified as the above-mentionedsolvents (u). Preferable examples among (u) are tetrahydrofuran,toluene, acetone, methyl ethyl ketone and ethyl acetate and morepreferably ethyl acetate in terms of film formation.

The solvent concentration in the water-based resin dispersion at thetime of dissolving (A) in the solvent is preferably in a range of 3 to60%, more preferably in a range of 10 to 45%, and even more preferablyin a range of 15 to 30%. The dissolution is carried out by stirring thewater-based resin dispersion for, for example, 1 to 10 hours and thetemperature at the time of dissolution is preferably in a range of 15 to45° C. and more preferably in a range of 15 to 30° C.

In the case the film is formed on the surfaces of (B) by melting (A),the content [the content of the components other than water and thesolvent] of the solid matter in the water-based resin dispersion (X1) isadjusted to be preferably in a range of 1 to 50% and more preferably 5to 30%. In this case, the content of the solvent is preferably 2% orless, more preferably 1% or less, and even more preferably 0.5% or less.If the solid matter content in (X1) is high or the solvent contentexceeds 2%, agglomerates may possibly be formed if (X1) is heated to 60°C. or higher. The conditions of the heating at the time of melting arenot particularly limited if they are suitable for melting (A), forexample, a method of heating preferably at 40 to 100° C., morepreferably 60 to 90° C., and even more preferably 60 to 80° C. forpreferably 1 to 300 minutes under stirring condition can be exemplified.

Additionally, a method of the treatment for film formation, a preferableheating treatment temperature in the case of obtaining the resinparticles (C21) with smooth surfaces by heating the water-baseddispersion (X1) of the resin particles (C1) with a solvent content of 2%or lower and thereby melting (A) on the core (Q) is preferably in atemperature range of Tg or higher of (P) and 80° C. or lower. If theheating treatment temperature is lower than Tg of (P), the surfacesmoothness of the resin particles (C21) is scarcely changed. If theheating treatment temperature is carried out at a temperature exceeding80° C., the shell (P) may possibly be peeled off the core.

A preferable method between the methods of film formation of (A) is themethod of melting (A) and combination of the method of dissolving (A)and the method of melting (A).

The resin particles (C1) are obtained by dispersing a resin (b), asolvent solution of (b), a precursor (b0) of the resin (b) or a solventsolution of (b0) in the water-based dispersion (W) of the resinparticles (A) comprising the resin (a); further forming resin (b) byreaction of (b0) in the case of using (b0); thereby obtaining thewater-based dispersion (X1) of the resin particles (C1) with a structurecomposed of the resin particles (B) comprising the resin (b) bearing theresin particles (A) on the surfaces thereof and/or the water-based resindispersion (X2) of the resin particles (C2) with a structure composed ofthe resin particles (B) bearing the film formed by resin particles (A)on the surfaces thereof; and finally removing the water-based solventfrom the water-based resin dispersion (X1) or (X2) [hereinafter, (X1) or(X2) are referred to as (X) in some cases]. Examples of the method forremoving the water-based solvent from the water-based dispersion are thesame as exemplified for the methods for removing the water-based solventfrom the water-based dispersion of (C2) in accordance with theproduction method for the resin particles of the first invention.

The resin particles (C1) are practically composed of relatively smallresin particles (A) and relatively large resin particles (B) and existin form of (B) bearing (A) on the surfaces. The resin particles (C21)are particles obtained by attaching (A) to (B), dissolving and/ormelting them, and thereby forming film made from (A) on the surfaces of(B).

In the case the attraction power of both particles is to be increased,it is effective to give mutually opposed electric charge to (A) and (B);to use a surfactant (s) or a water-soluble polymer (t) having opposedelectric charged to that of (A) and (B) in the case both (A) and (B)have the same electric charge; or to lower the sp value difference ofthe resin (a) and the resin (b) as much as possible within theabove-mentioned range (e.g. 2 or lower).

In terms of the particle diameter evenness and the storage stability ofthe resin particles (C), the resin particles (C) are composed ofpreferably 0.01 to 60% of (A) and 40 to 99.99% of (B); more preferably0.1 to 50% of (A) and 50 to 99.9% of (B); and even more preferably 1 to45% of (A) and 55 to 99% of (B).

In terms of the particle diameter evenness, the powder flowability, andthe storage stability of the resin particles (C1), the resin particles(B) are covered with the resin particles (A) at a ratio of preferably 5%or higher, more preferably 30% or higher, further more preferably 50% orhigher, and even more preferably 80% of the surface. The surfacecoverage of (C1) is calculated according to the following equation fromthe results of image analysis of an image obtained by a scanningelectron microscope (SEM).

Surface coverage (%)=[surface area of portion covered with the resinparticles (A)/surface area of portion covered with the resin particles(A)+exposed portion of the resin particles (B)]×100. In this connectionthe surface coverage of (C21) is same as (C2) of the first invention.

In terms of the particle diameter evenness, the coefficient of variationof the volume distribution of the resin particles (C) is preferably 30%or lower and more preferably 0.1 to 15%.

In terms of the particle diameter evenness, the value [volume averageparticle diameter/number average particle diameter] of the resinparticles (C) is preferably 1.0 to 1.4 and more preferably 1.0 to 1.2.

The volume average particle diameter of (C) differs depending on uses,however it is generally preferable in the range from 0.1 to 300 μm. Theupper limit is more preferably 250 μm and even more preferably 200 μmand the lower limit is more preferably 0.5 μm and even more preferably 1μm.

The volume average particle diameter and the number average particlediameter can be measured simultaneously by Multisizer III (manufacturedby Coulter).

The resin particles (C) of the invention may be provided with desiredsurface roughness by changing the particle diameters of the resinparticles (A) and the resin particles (B), the surface coverage of theresin particles (B) with the resin particles (A), or the surfacecoverage of core layer (Q) with shell layer (P). In the case powderflowability is improved, the BET specific surface area of (C) ispreferably 0.5 to 5.0 m²/g. The BET specific surface area in theinvention is measured (measurement gas: He/Kr=99.9/0.1 vol. %,calibration gas: nitrogen) by a specific surface area meter, forexample, QUANTASORB (manufactured by Yuasa Ionics Corp.)

Similarly, in terms of the powder flowability, the centerline averagesurface roughness Ra of (C) is preferably 0.01 to 0.8 μm. Ra is a valuecalculated by arithmetically averaging the absolute values of thedeviation of the roughness curve from the center line thereof and can bemeasured by, for example, a scanning type probe microscopic system(manufactured by Toyo Corp.).

The shape of the resin particles (C) is preferably spherical in terms ofthe powder flowability and melt leveling property. In that case,particles (A) and particles (B) are also preferable to be spherical. Theaverage degree of circularity of (C) is preferably 0.95 to 1.00. Theaverage degree of circularity is more preferably 0.96 to 1.0 and evenmore preferably 0.97 to 1.0. The average degree of circularity is avalue calculated by optically detecting particles and dividing by thecircumferential length of the corresponding circle having equivalentprojected area. Practically, a flow type particle image analyzer(FPIA-2000; manufactured by Sysmex Corp.) is used for the measurement. Aprescribed container is filled with 100 to 150 ml of water previouslysubjected to impurity solid matter removal and 0.1 to 0.5 ml of asurfactant (Dry Well: manufactured by Fuji Photo Film Co., Ltd.) as adispersant is added and further 0.1 to 9.5 g of a sample to be measuredis added. The suspension in which the sample is dispersed is treated byan ultrasonic disperser (Ultrasonic Cleaner Model VS-150: manufacturedby Velvo-Clear) for about 1 to 3 minutes for dispersion to adjust thedispersion concentration of 3,000 to 10,000 μL and thus the shape andthe distribution of a toner are measured.

In the second, third, fourth, eighth and tenth inventions, and in theproduction method (I) to obtain the resin particles of the firstinvention, the resin particles (C) of the invention may be provided withsmooth surface or desired surface roughness by changing the particlediameter ratio of the resin particles (A) and the resin particles (B),the surface coverage of the resin particles (B) with the resin particles(A) in water-based resin dispersion (X1), or the depth in which theresin particles (A) buried in the resin particles (B) in the interfaceof the resin particles (B)/water-based solvent in water-based resindispersion (X1).

The surface coverage of the resin particles (B) with the resin particles(A), or the depth in which the resin particles (A) buried in the resinparticles (B) can be controlled by the following methods.

[1]: At the time of producing water-based resin dispersion (X1), if theresin particles (A) and the resin particles (B) are made to havemutually opposed electric charge, the surface coverage and the depthbecome high. If the electric charge of the resin particles (A) and theresin particles (B) are made higher, the surface coverage and the depthbecomes higher.[2]: At the time of producing water-based resin dispersion (X1), if bothof the resin particles (A) and the resin particles (B) are made to haveelectric charge with the mutually same polarity (both are made positiveor both are made negative), the surface coverage tends to be low and thedepth tends to be shallow. In this case, generally if the surfactant (s)and/or the water-soluble polymer (t) [particularly having opposedelectric charge to that of the resin particles (A) and the resinparticles (B)] is used, the coverage is increased. Also, in the case thewater-soluble polymer (t) is used, the depth becomes deeper as themolecular weight of the water-soluble polymer (t) is higher.[3]: At the time of producing water-based resin dispersion (X1), if theresin (a) is a resin having an acidic functional group such as carboxyl,phosphoric acid group, and sulfonic acid group (generally it ispreferable that the molecular weight per one acidic functional group is1,000 or lower), the coverage and the depth become higher as the pH ofthe water-based solvent is lower. On the contrary, the coverage and thedepth become smaller as the pH of the water-based solvent is higher.[4]: At the time of producing water-based resin dispersion (X1), if theresin (a) is a resin having a basic functional group such as primaryamino group, secondary amino group, tertiary amino group, and quaternaryammonium group (generally it is preferable that the molecular weight perone basic functional group is 1,000 or lower), the coverage and thedepth become higher as the pH of the water-based solvent is higher. Onthe contrary, the coverage and the depth become smaller as the pH of thewater-based solvent is lower.[5]: The coverage and the depth become higher if the sp value differenceof the resin particles (a) and the resin particles (b) is made narrower.

The resin particles (A) and/or (B) composing the resin particles (C) maycontain additives (a pigment, a filler, an antistatic agent, a coloringagent, a releasing agent, a charge controlling agent, an ultravioletabsorbent, an antioxidant, an antiblocking agent, a thermal resistantstabilizer, and a flame retardant). As a method for adding the additivesto (A) or (B), they may be added at the time of producing thewater-based resin dispersion (X1) in the water-based solvent, however itis more preferable that the resin (a) or the resin (b) is previouslymixed with the additives and then the mixture of them is added to thewater-based solvent and disperse it in the solvent.

Further, in the invention, the additives are not necessarily added atthe time of forming the particles in the water-based solvent, they maybe added after formation of the particles. For example, after theparticles containing no coloring agent are formed, a coloring agent maybe added by a conventionally known dyeing method or the particles may beimpregnated with the above-mentioned additives together with the solvent(u) and/or the plasticizer (v).

If the resin particles (A) contain a charge controlling agent containingthe above-mentioned organic acid salt (m) as an additive, theelectrostatic property is improved and it is therefore preferable.

As (m), those same as described above can be exemplified and the useamount is also same.

Generally in the inventions, particularly in the third invention, if awax (c) and a modified wax (d) comprising grafting vinyl polymer chainsare added in combination with the resin (b) in the resin particles (B),the thermal resistant storage stability is further improved andtherefore it is preferable.

The content of (c) in (B) is preferably 20% or lower and more preferablyin a range of 1 to 15%. The content of (d) is preferably 10% or lowerand more preferably in a range of 0.5 to 8%. The total content of (c)and (d) is preferably 25% or lower and more preferably in a range of 1to 20%.

The wax (c) is dispersed in the resin (b) after previously beingmelt-kneaded with the modified wax (d) in absence of a solvent and/orbeing thermally dissolved and mixed with the modified wax (d) in thepresence of a solvent.

Examples usable as the wax (c) may include polyolefin waxes, paraffinwaxes, carbonyl-containing waxes and their mixtures and particularlypreferable waxes among them are paraffin wax (c1). Examples of (c1) arepetroleum type waxes containing mainly linear saturated hydrocarbonshaving 20 to 36 carbon atoms and having a melting point in a range of 50to 90° C.

In terms of the releasing property, Mn of (c) is preferably 400 to 5000,more preferably 1000 to 3000, and even more preferably 1500 to 2000. Inthe above-mentioned description and hereinafter, Mn of the wax ismeasured by GPC (solvent: o-dichlorobenzene, standard substance:polystyrene).

The wax (c) is preferable to be dispersed in the resin (b) afterpreviously being melt-kneaded in absence of a solvent and/or beingthermally dissolved and mixed with the modified wax (d) comprisinggrafting vinyl polymer chains in the presence of a solvent (u). By thismethod, at the time of wax dispersion, coexistence of the modified wax(d) makes it possible to adsorb the wax moiety of (d) in the surface of(c) or partially entangle of the modified wax (d) in the matrixstructure of the wax and the wax (c) surface and the resin (b) becomemutually affinitive and (c) can be included more evenly in the resinparticles (B) and thus control of the dispersion state is made easy.

The modified wax (d) comprises a wax grafted with vinyl polymer chains.Examples to be used as wax for (d) are those same as exemplified for theabove-mentioned wax (c) and preferable examples are also same. The vinylmonomers composing the vinyl polymer chains of (d) are same as theexemplified monomers (1) to (10) composing the above-mentioned vinylresins and particularly preferable monomers among them are monomers (1),(2), and (6). The vinyl polymer chains may be homopolymers andcopolymers of the vinyl monomers.

The amount of the wax component (including un-reacted wax) in themodified wax (d) is preferably 0.5 to 99.5%, more preferably 1 to 80%,furthermore preferably 5 to 50%, and even more preferably 10 to 30%. Tgof (d) is preferably 40 to 90° C. and more preferably 50 to 80° C. interms of the thermal resistant storage stability of the resin particles(C).

Mn of (d) is preferably 1500 to 10000 and more preferably 1800 to 9000.If Mn is in a range of 1500 to 10000, the mechanical strength of theresin particles (C) is high.

The modified wax (d) is obtained by dissolving or dispersing the wax (c)in a solvent (e.g., toluene or xylene), heating the wax at 100 to 200°C., dropwise adding vinyl monomers with a peroxide type initiator (e.g.,benzoyl peroxide, di-tert-butyl peroxide, and tert-butyl peroxidebenzoate), polymerizing the monomers, and then removing the solvent.

The amount of the peroxide type initiator in the synthesis of themodified wax (d) is preferably 0.2 to 10% and more preferably 0.5 to 5%on the basis of the total weight of the raw materials of (d).

Oil-soluble polymerization initiators and water-soluble polymerizationinitiators may be used as peroxide polymerization initiator.

Practical examples of the initiators may include those mentioned above.

A method for mixing the wax (c) and the modified-wax (d) may include [1]a method of melting and kneading them at a temperature equal to orhigher than their melting points; [2] a method of dissolving orsuspending (c) and (d) in the solvent (u), precipitating in the solutionby cooling crystallization or solvent crystallization or deposition in agas by spray drying; and [3] a method of dissolving or suspending (c)and (d) in the solvent (u) and mechanically wet-pulverizing them by adispersing apparatus. The method [2] is preferable among them.

A method of dispersing the wax (c) and the modified wax (d) in (b) maybe a method of obtaining respective solvent solutions or dispersions of(c) and (d) in (b) and mixing them.

EXAMPLES

Hereinafter, the inventions will be described more in detail withreference to examples, however it is not intended that the inventions belimited to the illustrated examples. In the following description,“part” denotes part by weight without otherwise specified.

Production Example 1 Production of Water-Based Dispersion of ResinParticle (A)

At first, 130 parts of isopropanol was loaded into a reaction containerequipped with a stirrer and a thermometer and in stirring condition, amixed solution containing 80 parts of styrene, 85 parts of methacrylicacid, 120 parts of butyl acrylate, and 62 parts of benzoyl peroxide(containing 25% of water) was dropwise added for 120 minutes. Further,in stirring condition, 50 parts of the obtained polymerization solutionwas dropwise added to 60 parts of ion water to obtain a water-baseddispersion [fine particle dispersion W1]. The volume average particlediameters of [fine particle dispersion W1] measured by LA-920 andELS-800 were both 0.09 μm. A portion of [fine particle dispersion W1]was dried to isolate a resin component. The Tg of the resin componentmeasured by DSC was 72° C. and the initial softening temperature was 98°C., and the flow temperature was 175° C.

Production Example 2 Production of Water-Based Dispersion of ResinParticle (A)

A reaction vessel equipped with a condenser tube, a stirrer, and anitrogen introduction pipe was filled with 377 parts of 1,2-propyleneglycol (hereinafter, referred to as propylene glycol), 350 parts ofdimethyl terephthalate, 40 parts of adipic acid, and as a condensationcatalyst 0.3 parts of tetrabutoxytitanate and reaction of the mixturewas carried out at 180° C. for 8 hours under nitrogen flowing conditionwhile produced methanol was being removed. Next, while the reactionproduct was gradually heated to 230° C., the reaction was carried outfurther for 4 hours under nitrogen flowing condition while producedpropylene glycol and water were being removed and further reaction wascontinued under reduced pressure of 5 to 20 mmHg and at the moment thevalue 1000 Pa·s measured by a flow tester was read at 85° C., thereaction product was taken out. After the taken out resin was cooled toa room temperature, it was pulverized and granulated to obtain[polyester b0]. Mw of [polyester b0] was 3200. Next, 30 parts of acetonewas added to 30 parts of [polyester b0] and further 2.5 parts oftriethylamine was added. Further, 90 parts of water was added to theobtained solution which was well stirred to obtain a water-baseddispersion of polyester resin [fine particle dispersion W2]. The volumeaverage particle diameter of [fine particle dispersion W2] measured byELS-800 was 0.05 μm. A portion of [fine particle dispersion W2] wasdried and resin component was isolated and the glass transitiontemperature, the initial softening temperature, and the flow temperatureof the obtained resin component measured by a flow tester were 60° C.,90° C., and 155° C., respectively.

Production Example 3 Production of Water-Based Dispersion of ResinParticle (A)

A reaction container equipped with a stirrer and a thermometer wasfilled with 753 parts of water, 8 parts of alkylallylsulfosuccinic acidsodium salt (Eleminol JS-2, manufactured by Sanyo Chemical Industries,Ltd.), 58 parts of styrene, 58 parts of methacrylic acid, 77 parts ofbutylacrylate, 1 part of ammonium persulfate, and 9 parts of asurfactant (polyoxysorbitan monooleate) and the mixture was stirred at400 rpm for 15 minutes to obtain a white emulsion. The emulsion washeated to 75° C. inner temperature and reaction was carried out for 5hours. Further, 30 parts of an aqueous 1% ammonium persulfate solutionwas added and the reaction mixture was aged at 75° C. for 5 hours toobtain a water-based dispersion of vinyl resin (styrene-methacrylicacid-butyl acrylate-sodium alkylallylsulfosuccinate copolymer) [fineparticle dispersion W3]. The volume average particle diameters of [fineparticle dispersion W3] measured by LA-920 and ELS-800 were both 0.05μm. A portion of [fine particle dispersion W3] was dried and resincomponent was isolated and the Tg, the initial softening temperature,and the flow temperature of the obtained resin component measured by DSCwere 60° C., 110° C., and 198° C., respectively.

Production Example 4 Production of Water-Based Dispersion of ResinParticle (A)

At first, 132 parts of isopropanol was loaded into a reaction containerequipped with a stirrer and a thermometer and in stirring condition, amixed solution containing 82 parts of styrene, 82 parts of methacrylicacid, 109 parts of butyl acrylate, and 60 parts of benzoyl peroxide(containing 25% of water) was dropwise added for 120 minutes. Further,in stirring condition, 50 parts of the obtained polymerization solutionwas dropwise added to 60 parts of ion water to obtain a water-baseddispersion [fine particle dispersion W4]. The volume average particlediameters of [fine particle dispersion W4] measured by LA-920 andELS-800 were both 0.10 μm. A portion of [fine particle dispersion W4]was dried and resin component was isolated and the Tg, the initialsoftening temperature, and the flow temperature of the obtained resincomponent measured by DSC were 75° C., 100° C., and 160° C.,respectively.

Production Example 5 Production of Water-Based Dispersion of ResinParticle (A)

At first, 150 parts of isopropanol was loaded into a reaction containerequipped with a stirrer and a thermometer and in stirring condition, amixed solution containing 91 parts of styrene, 91 parts of methacrylicacid, 122 parts of butyl acrylate, and 1.0 part of benzoyl peroxide(containing 25% of water) was dropwise added for 120 minutes. Further,in stirring condition, 50 parts of the obtained polymerization solutionwas dropwise added to 60 parts of ion water to obtain a water-baseddispersion [fine particle dispersion W5]. The volume average particlediameters of [fine particle dispersion W5] measured by LA-920 andELS-800 were both 0.10 μm. A portion of [fine particle dispersion W5]was dried and resin component was isolated and the Tg, the initialsoftening temperature, and the flow temperature of the obtained resincomponent measured by DSC were 95° C., 120° C., and 225° C.,respectively.

Production Example 6 Production of Water-Based Dispersion of ResinParticle (A)

A water-based dispersion of vinyl resin (styrene-butylacrylate-methacrylic acid-Zn methacrylate-sodiumalkylallylsulfosuccinate copolymer) [fine particle dispersion W6] wasobtained in the same production manner as the Production Example 3,except that 58 parts of methacrylic acid was changed to 38 parts ofmethacrylic acid and 20 parts of Zn methacrylate. The volume averageparticle diameters of the fine particle dispersion measured by LA-920and ELS-800 were both 0.08 μm. A portion of [fine particle dispersionW6] was dried and resin component was isolated and the Tg of theobtained resin component measured by DSC was 72° C.

Production Example 7 Production of Resin (b)

[Synthesis of Linear Polyester]

At first, 701 parts (18.8 mole) of propylene glycol, 716 parts (7.5mole) of terephthalic acid dimethyl ester, 180 parts (2.5 mole) ofadipic acid, and as a condensation catalyst, 3 parts of tetrabutoxytitanate were loaded into a reaction vessel equipped with a condensertube, a stirrer, and a nitrogen introduction tube and under nitrogenflow, while produced methanol are removed, reaction was carried out for8 hours. Successively, while the temperature was gradually heated to230° C. and produced propylene glycol and water was being removed undernitrogen flow, reaction was carried out for 4 hours and further reactionwas continued in reduced pressure of 5 to 20 mmHg and when the softeningpoint reached 150° C., the reaction product was taken out. The recoveredpropylene glycol was 316 parts (8.5 mole). After the taken out resin wascooled to a room temperature, the resin was pulverized and granulated toobtain [polyester b]. Mn of [polyester b] was 8000.

The number of mole in the parenthesis ( ) means the relative mole ratio,hereinafter the same.

Production Example 8 Production of Resin (b)

[Synthesis of Non-Linear Polyester]

At first, 557 parts (17.5 mole) of propylene glycol, 569 parts (7.0mole) of terephthalic acid dimethyl ester, 184 parts (3.0 mole) ofadipic acid, and as a condensation catalyst, 3 parts of tetrabutoxytitanate were loaded into a reaction vessel equipped with a condensertube, a stirrer, and a nitrogen introduction tube and under nitrogenflow, while produced methanol are removed, reaction was carried out for8 hours. Successively, while the temperature was gradually heated to230° C. and produced propylene glycol and water was being removed undernitrogen flow, reaction was carried out for 4 hours and furthercontinued for 1 hour in reduced pressure of 5 to 20 mmHg. The recoveredpropylene glycol was 175 parts (5.5 mole). After the reaction system wascooled to 180° C. and 121 parts (1.5 mole) of trimellitic anhydride wasadded and reaction was carried out for 2 hours at normal pressure inclosed state and further continued at 220° C. and normal pressure andwhen the softening point reached 180° C., the product was taken out andcooled to a room temperature and pulverized and granulated to obtain[polyester b2]. Mn of [polyester b2] was 8500.

Production Example 9

At first, 2000 parts of polycaprolactonediol (Placcel L 220AL,manufactured by Dicel Chemical Industry, Ltd.) having a hydroxyl valueof 56 was loaded into a reaction container equipped with a stirrer and athermometer and heated to 110° C. for dehydration at a reduced pressureof 3 mmHg for 1 hour. Successively, 457 parts of IPDI was added andreaction was carried out at 110° C. for 10 hours to obtain [urethaneprepolymer 1] having isocyanate groups at terminals. The NCO content of[urethane prepolymer 1] was 3.6%.

Production Example 10

A reaction container equipped with a stirrer and a thermometer wasfilled with 50 parts of ethylenediamine and 300 parts of MIBK andreaction was carried out at 50° C. for 5 hours to obtain a ketiminecompound [curing agent 1].

Production Example 11 Production of Resin (b)

At first, 452 parts of xylene was loaded into an autoclave reactionvessel equipped with a thermometer, a stirrer, and a nitrogenintroduction tube and after replacement with nitrogen, a mixture of amonomer mixture containing 845 parts of styrene and 155 parts of n-butylacrylate with as an initiator 6.4 parts of di-tert-butyl peroxide, and125 parts of xylene was dropwise added at 170° C. for 3 hours. After thedropwise addition, the reaction mixture was aged at 170° C. for 1 hourto complete polymerization. After that, under a reduced pressure,desolvation was carried out to obtain a resin [vinyl resin b3]. Theweight average molecular weight of [vinyl resin b3] by GPC was 14,000and the glass transition temperature was 60° C.

Production Example 12 Production of Resin (b)

A reaction container equipped with a condenser tube, a stirrer, and anitrogen introduction tube was filled with 343 parts of bisphenol A-2mole EO adduct, 166 parts of isophthalic acid, and 2 parts of dibutyltinoxide and reaction of the mixture was carried out at 230° C. and normalpressure for 8 hours and further in reduced pressure of 10 to 15 mmHgfor 5 hours and after that the reaction mixture was cooled to 110° C.and further reacted with 17 parts of isophorone diisocyanate in tolueneat 110° C. for 5 hours and successively, desolvation was carried out toobtain a resin [urethane-modified polyester b4] with a weight averagemolecular weight of 72,000 and a NCO content of 0.7%.

Production Example 13 Production of Resin (b)

[Polyester b5] which was not modified and had Mn of 2,400, hydroxylvalue of 51, and acid value of 5 was obtained in the same manner asProduction Example 12, except that 570 parts of bisphenol A-2 mole EOadduct and 217 parts of terephthalic acid were used and condensationpolymerization was carried out at 230° C. and normal pressure for 6hours.

Production Example 14 Production of Colorant Dispersion

A beaker was filled with 20 parts of copper phthalocyanine, 4 parts of acolorant dispersant (Solsperse 28000, manufactured by Avecia KK), 20parts of [polyester b2], and 56 parts of ethyl acetate and the mixturewas evenly stirred and dispersed and then the copper phthalocyanine wasmicro-dispersed by Beads-mill to obtain [colorant dispersion 1]. Thevolume average particle diameter of the [colorant dispersion 1] measuredby LA-920 was 0.3 μm.

Production Example 15 Production of Colorant Dispersion

A beaker was filled with 20 parts of copper phthalocyanine, 4 parts of acolorant dispersant (Solsperse 28000, manufactured by Avecia KK), and 76parts of ethyl acetate and the mixture was evenly stirred and dispersedand then the copper phthalocyanine was micro-dispersed by Beads-mill toobtain [colorant dispersion 2]. The volume average particle diameter ofthe [colorant dispersion 2] measured by LA-920 was 0.3 μm.

Production Example 16 Production of Modified Wax

At first, 454 parts of xylene and 150 parts of low molecular weightpolyethylene (Sanwax LEL-400, manufactured by Sanyo Chemical Industries,Ltd.: softening point 128° C.) were loaded into an autoclave reactionvessel equipped with a thermometer and a stirrer and the inside gas wasreplace with nitrogen, the temperature was heated 170° C. tosufficiently dissolve these compounds and a mixed solution containing595 parts of styrene, 255 parts of methyl methacrylate, 34 parts ofdi-tert-butyl peroxyhexahydroterephthalate, and 119 parts of xylene wasdropwise added at 170° C. for 3 hours and polymerization was carried outand the reaction mixture was kept at the temperature for 30 minutes.Next, desolvation was carried out to obtain [modified wax 1]. The[modified wax] had an sp value of graft chains of 10.35 (cal/cm³)^(1/2),1872 for Mn, 5194 for Mw, and 56.9° C. for Tg.

Production Example 17 Production of Wax Dispersion

At first, 10 parts of paraffin wax (melting point 73° C.), 1 part of[modified wax 1], and 33 parts of ethyl acetate were loaded into areaction container equipped with a thermometer and a stirrer and heated78° C. to sufficiently dissolve these compounds and cooled to 30° C. bytaking 1 hour to crystallize the wax in finely granular state and thewax was further wet-pulverized by Ultra Viscomill (manufactured byAIMEX) to obtain [wax dispersion 1].

Production Example 18 Production of Resin Solution

At first, 10 parts of [polyester b1] and 10 parts of ethyl acetate wereloaded into a reaction container equipped with a thermometer and astirrer and stirred to evenly disperse these compounds to obtain [resinsolution 1].

Production Example 19 Production of Resin Solution

At first, 10 parts of [polyester b2] and 10 parts of ethyl acetate wereloaded into a reaction container equipped with a thermometer and astirrer and stirred to evenly disperse these compounds to obtain [resinsolution 2].

Production Example 20 Production of Resin Solution

At first, 10 parts of [vinyl resin b3] and 10 parts of ethyl acetatewere loaded into a reaction container equipped with a thermometer and astirrer and stirred to evenly disperse these compounds to obtain [resinsolution 3].

Production Example 21 Production of Resin Solution

[Resin solution 4] was obtained by dissolving and mixing 200 parts of[urethane-modified polyester b4] and 800 parts of [polyester b5] in1,800 parts of ethyl acetate. A portion of [resin solution 4] was driedin reduced pressure to isolate the resin component. Tg of the resincomponent measured by DSC was 55° C.

Example 1

A beaker was filled with 48 parts of [resin solution 1], 12 parts of[resin solution 2], 27 parts of [wax dispersion 1], and 10 parts of[colorant dispersion 1] and the mixture was stirred at 25° C. and 8,000rpm by TK type homomixer to evenly dissolve and disperse the mixture andobtain [resin solution 1A]

A beaker was filled with 97 parts of ion exchanged water, 15.4 parts of[fine particle dispersion W1], 1 part of carboxymethyl cellulose sodiumsalt, and 10 parts of an aqueous solution of 48.5% of dodecyldiphenylether disulfonic acid sodium salt (Eleminol MON-7, manufactured by SanyoChemical Industries, Ltd.) and the mixture was evenly dissolved.Successively, while the mixture was stirred at 25° C. and 10,000 rpm byTK type homomixer, 75 parts of [resin solution 1A] was added and stirredfor 2 minutes. The resulting mixed solution was transferred to a flaskequipped with a stirrer and a thermometer and heated to 35° C. and ethylacetate was removed until the concentration reached to 0.5% or lower toobtain a water-based resin dispersion (XF1) of resin particles eachcomposed of a core layer (Q) of (B) and a shell layer (P) in a film-likeform made of (A) formed on the surface of the core layer. Next, thedispersion was filtered and the particles were dried at 40° C.×18 hoursto decrease the volatile component to 0.5% or less and obtain resinparticles (F1).

Example 2

A water-based resin dispersion (XF2) of resin particles each composed of(Q) and (P) formed on the surface of (Q) and resin particles (F2) wereobtained in the same manner as Example 1, except that [fine particledispersion W2] 12.3 parts was used in place of [fine particle dispersionW1] 15.4 parts of Example 1.

Example 3

A beaker was filled with 48 parts of [resin solution 1], 6 parts of[prepolymer 1], 0.2 parts of [curing agent 1], 27 parts of [waxdispersion 1], and 10 parts of [colorant dispersion 1] and the mixturewas stirred at 25° C. and 8,000 rpm by TK type homomixer to evenlydissolve and disperse the mixture and obtain [resin solution 1B].

A beaker was filled with 97 parts of ion exchanged water, 10.5 parts of[fine particle dispersion W1], 1 part of carboxymethyl cellulose sodiumsalt, and 10 parts of an aqueous solution of 48.5% of dodecyldiphenylether disulfonic acid sodium salt (Eleminol MON-7, manufactured by SanyoChemical Industries, Ltd.) and the mixture was evenly dissolved.Successively, while the mixture was stirred at 25° C. and 10,000 rpm byTK type homomixer, 75 parts of [resin solution 1B] was added and stirredfor 2 minutes. The resulting mixed solution was transferred to a flaskequipped with a stirrer and a thermometer and heated to 35° C. and ethylacetate was removed until the concentration reached to 0.5% or lower toobtain a water-based resin dispersion (XF3) of resin particles eachcomposed of a core layer (Q) of (B) and a shell layer (P) in a film-likeform made of (A) formed on the surface of the core layer. Next, thedispersion was filtered and the particles were dried at 40° C.×18 hoursto decrease the volatile component to 0.5% or less and obtain resinparticles (F3).

Example 4

A water-based resin dispersion (XF4) of resin particles each composed of(Q) bearing (P) on the surface thereof and resin particles (F4) wereobtained in the same manner as Example 3, except that [fine particledispersion W2] was used in place of [fine particle dispersion W1] ofExample 3.

Example 5

A beaker was filled with 60 parts of [resin solution 3], 27 parts of[wax dispersion 1], and 10 parts of [colorant dispersion 1] and themixture was stirred at 25° C. and 8,000 rpm by TK type homomixer toevenly dissolve and disperse the mixture and obtain [resin solution 3A].

A beaker was filled with 97 parts of ion exchanged water, 10.5 parts of[fine particle dispersion W1], 1 part of carboxymethyl cellulose sodiumsalt, and 10 parts of an aqueous solution of 48.5% of dodecyldiphenylether disulfonic acid sodium salt (Eleminol MON-7, manufactured by SanyoChemical Industries, Ltd.) and the mixture was evenly dissolved.Successively, while the mixture was stirred at 25° C. and 10,000 rpm byTK type homomixer, 75 parts of [resin solution 3A] was added and stirredfor 2 minutes. The resulting mixed solution was transferred to a flaskequipped with a stirrer and a thermometer and heated to 35° C. and ethylacetate was removed until the concentration reached to 0.5% or lower toobtain a water-based resin dispersion (XF5) of resin particles eachcomposed of a core layer (Q) of (B) and a shell layer (P) in a film-likeform made of (A) formed on the surface of the core layer. Next, thedispersion was filtered and the particles were dried at 40° C.×18 hoursto decrease the volatile component to 0.5% or less and obtain resinparticles (F5).

Example 6

A water-based resin dispersion (XF6) of resin particles each composed of(Q) bearing (P) on the surface thereof and resin particles (F6) wereobtained in the same manner as Example 5, except that [fine particledispersion W2] was used in place of [fine particle dispersion W1] ofExample 5.

Example 7

A beaker was filled with 60 parts of [resin solution 1], 27 parts of[wax dispersion 1], and 10 parts of [colorant dispersion 1] and themixture was stirred at 25° C. and 8,000 rpm by TK type homomixer toevenly dissolve and disperse the mixture and obtain [resin solution 1C].

A beaker was filled with 97 parts of ion exchanged water, 11 parts of[fine particle dispersion W4], 1 part of carboxymethyl cellulose sodiumsalt, and 10 parts of an aqueous solution of 48.5% of dodecyldiphenylether disulfonic acid sodium salt (Eleminol MON-7, manufactured by SanyoChemical Industries, Ltd.) and the mixture was evenly dissolved.Successively, while the mixture was stirred at 25° C. and 10,000 rpm byTK type homomixer, 75 parts of [resin solution 1C] was added and stirredfor 2 minutes. The resulting mixed solution was transferred to a flaskequipped with a stirrer and a thermometer and heated to 35° C. and ethylacetate was removed until the concentration reached to 0.5% or lower toobtain a water-based resin dispersion (XF7) of resin particles eachcomposed of a core layer (Q) of (B) and a shell layer (P) in a film-likeform made of (A) formed on the surface of the core layer. Next, thedispersion was filtered and the particles were dried at 40° C.×18 hoursto decrease the volatile component to 0.5% or less and obtain resinparticles (F7).

Example 8

The water-based resin dispersion (XF7) obtained in Example 7 was heatedto 70° C. in stirring condition and continuously stirred for 1 hour andthen cooled to 25° C. to obtain a water-based resin dispersion (XF8) ofresin particles each composed of a core layer (Q) of (B) and a shelllayer (P) in a more film-like form made of (A) formed on the surface ofthe core layer. Next, same filtration and drying process was carried outto obtain resin particles (F8).

Example 9

A beaker was filled with 276 parts of [resin solution 4], as a releasingagent 10 parts of trimethylolpropane tribehenate (melting point 58° C.and melt viscosity 24 cps), and 25 parts of [colorant dispersion 2] andthe mixture was stirred at 25° C. and 12,000 rpm by a TK type homomixerand evenly dissolved and dispersed to obtain [resin solution 4A].

A beaker was filled with 443 parts of ion-exchanged water, 15 parts of[fine particle dispersion W6], 2 parts of carboxymethyl cellulose sodiumsalt, 40 parts of an aqueous solution of 48.5% sodium dodecyl diphenylether disulfonate (Eleminol MON-7, manufactured by Sanyo ChemicalIndustries, Ltd.) and the mixture was evenly dissolved. Next, understirring condition at 25° C. and 12,000 rpm by a TK type homomixer, 300parts of [resin solution 4A] was added and stirred for 10 minutes.Successively, the obtained mixture was transferred to a flask equippedwith a stirrer and a thermometer and heated to remove ethyl acetate andfurther heated to 70° C. and reacted for 5 hours to obtain a water-basedresin dispersion (XF9) of resin particles each composed of a core layer(Q) of (B) and (A) adhering on the core surface. Next, the dispersionwas filtered and the product was dried in condition of 40° C.×18 hoursto decrease the volatile component to 0.5% or lower and obtain resinparticles (F9).

Example 10

The water-based resin dispersion (XF 9) obtained in Example 9 was heatedto 70° C. and stirred for 1 hour and then cooled to 25° C. to obtain awater-based resin dispersion (XF 10) of resin particles each composed ofa core layer (Q) of (B) and a shell layer (P) in a film-like form madeof (A) formed on the surface of the core layer. Next, filtration wascarried out in the same manner to obtain resin particles (F10).

Comparative Example 1

The water-based resin dispersion (XF1) obtained in Example 1 was heatedto 85° C. in stirring condition and continuously stirred for 1 hour andthen cooled to 25° C. to obtain a water-based resin dispersion (XF′1) inwhich (P) was peeled off (Q). Next, same filtration and drying processwas carried out to obtain resin particles (F′1) containing only (Q) andfrom which (P) was removed by the filtration.

Comparative Example 2

The water-based resin dispersion (XF2) obtained in Example 2 was heatedto 85° C. in stirring condition and continuously stirred for 1 hour andthen cooled to 25° C. to obtain a water-based resin dispersion (XF′2) inwhich (P) was peeled off (Q). Next, same filtration and drying processwas carried out to obtain resin particles (F′2) containing only (Q) andfrom which (P) was removed by the filtration.

Comparative Example 3

The water-based resin dispersion (XF′3) of resin particles each composedof a core layer (Q) of (B) and resin particles (A) adhering to thesurface of the core layer and the resin particles (F′3) were obtained inthe same manner as Example 2, except that [fine particle dispersion W3]2.9 parts was used in place of [fine particle dispersion W1] 15.4 partsin the Example 1.

Comparative Example 4

The water-based resin dispersion (XF3) obtained in Example 3 was heatedto 85° C. in stirring condition and continuously stirred for 1 hour andthen cooled to 25° C. to obtain a water-based resin dispersion (XF′4) inwhich (P) was peeled off (Q). Next, same filtration and drying processwas carried out to obtain resin particles (F′4) containing only (Q) andfrom which (P) was removed by the filtration.

Comparative Example 5

The water-based resin dispersion (XF4) obtained in Example 4 was heatedto 85° C. in stirring condition and continuously stirred for 1 hour andthen cooled to 25° C. to obtain a water-based resin dispersion (XF′5) inwhich (P) was peeled off (Q). Next, same filtration and drying processwas carried out to obtain resin particles (F′5) containing only (Q) andfrom which (P) was removed by the filtration.

Comparative Example 6

The water-based resin dispersion (XF5) obtained in Example 5 was heatedto 85° C. in stirring condition and continuously stirred for 1 hour andthen cooled to 25° C. to obtain a water-based resin dispersion (XF′6) inwhich (P) was peeled off (Q). Next, same filtration and drying processwas carried out to obtain resin particles (F′6) containing only (Q) andfrom which (P) was removed by the filtration.

Comparative Example 7

The water-based resin dispersion (XF6) obtained in Example 6 was heatedto 85° C. in stirring condition and continuously stirred for 1 hour andthen cooled to 25° C. to obtain a water-based resin dispersion (XF′7) inwhich (P) was peeled off (Q). Next, same filtration and drying processwas carried out to obtain resin particles (F′7) containing only (Q) andfrom which (P) was removed by the filtration.

Comparative Example 8

The water-based resin dispersion (XF′8) of resin particles each composedof a core layer (Q) of (B) and resin particles (A) adhering to thesurface of the core layer and the resin particles (F′8) were obtained inthe same manner as Example 7, except that [fine particle dispersion W5]was used in place of [fine particle dispersion W4] in the Example 7.

Comparative Example 9

After the water-based resin dispersion (XF′8) obtained in ComparativeExample 8 was heated to 70° C. in stirring condition and stirred for 1hour, the dispersion was cooled to 25° C. to obtain a water-based resindispersion (XF′9) of resin particles each composed of a core layer (Q)of (B) and (A) in slightly film-like form on the surface of the corelayer. Next, filtration and drying process was carried out in the samemanner to obtain resin particles (F′9).

Comparative Example 10

The water-based resin dispersion (XF′10) of resin particles eachcomposed of a core layer (Q) of (B) and resin particles (A) adhering tothe surface of the core layer and the resin particles (F′10) wereobtained in the same manner as Example 9, except that [fine particledispersion W3] was used in place of [fine particle dispersion W6] in theExample 9.

Physical Property Measurement

The resin particles (F1) to (F10) and (F′1) to (F′10) obtained inExamples 1 to 10 and Comparative Examples 1 to 10 were dispersed inwater and the particle size distribution was measured by Coultercounter. The average degree of circularity, the electrostatic property,the thermal resistance storage stability, and the low temperature fixingproperty of the resin particles were measured. The results are shown inTables 1 and 2. The mark ◯ shows that the defined points were foundwithin the quadrangular area ABCD and the mark x shows that the definedpoints were found out of the quadrangular area ABCD with respect to thesecond invention.

TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 Type of resin F1 F2 F3 F4 F5 F6 F7F8 F9 F10 particles Content of (A) in 8.1 10.8 8.1 10.8 8.1 10.8 6.0 6.02.3 2.3 resin particles (%) Attaching state Film- Film- Film- Film-Film- Film- Film- More Granular Film- of (A) like like like like likelike like film- like form form form form form form form like form formGlass transition 72 60 72 60 72 60 75 75 72 72 temperature of (a) (° C.)Initial softening 98 90 98 90 98 90 100 100 115 110 temperature of (a)(° C.) Flow temperature 175 155 175 155 175 155 160 160 205 198 of (a)(° C.) Difference of 103 95 103 95 103 95 85 85 133 126 glass transitiontemperature and flow temperature of (a) (° C.) Content of 9.8 0.2 9.80.2 9.8 0.2 9.8 9.8 9.8 9.8 carboxyl group in (a) (%) Neutralization 0100 0 100 0 100 0 0 0 0 ratio of carboxyl group in (a) (%) Δsp of resin(a) 0.4 0.3 0.8 0.7 0.6 0.5 0.5 0.5 1.1 1.1 and resin (b) Weight average6 4 6 4 6 4 6.2 6.2 270 270 molecular weight of (a) (×1000) In theinside of ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ X X quadrangular area ABCD Volume average 0.090.05 0.09 0.05 0.09 0.05 0.10 0.10 0.08 0.08 particle diameter of (A)(μm) Volume average 5.6 5.5 5.7 5.5 5.3 5.7 5.6 5.6 5.2 5.2 particlediameter of (C) (μm) Surface coverage 100 100 100 100 100 100 100 100 90100 (%) Volume average 1.17 1.18 1.17 1.17 1.14 1.16 1.18 1.18 1.12 1.12particle diameter/number average particle diameter of (C) Average degreeof 0.98 0.98 0.98 0.98 0.98 0.98 0.98 0.98 0.98 0.98 circularity of (C)Smoothness of ◯ ◯ ◯ ◯ ◯ ◯ ◯ ⊚ X ◯ particle surface of (C) Electrostatic−17 −26 −18 −22 −20 −21 −17 −17 −30 −30 charge (μC/g) Low temperature105 105 105 105 125 125 105 105 125 125 fixing property (° C.) Thermalresistant ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ storage stability

TABLE 2 Comparative Example 1 2 3 4 5 6 7 8 9 10 Type of resin particlesF′ 1 F′ 2 F′ 3 F′ 4 F′ 5 F′ 6 F′ 7 F′ 8 F′ 9 F′ 10 Content of (A) inresin particles 0 0 2.3 0 0 0 0 6.0 6.0 2.1 (%) Attaching state of (A)No No Granular No No No No Granular Slightly Granular adhesion adhesionadhesion adhesion adhesion adhesion film- like form Glass transition 7260 60 72 60 72 60 95 95 60 temperature of (a) (° C.) Initial softening98 90 110 98 90 98 90 120 120 110 temperature of (a) (° C.) Flowtemperature of (a) 175 155 198 175 155 175 155 225 225 198 (° C.)Difference of glass 103 95 138 103 95 103 95 130 130 138 transitiontemperature and flow temperature of (a) (° C.) Content of carboxyl group9.8 0.2 9.8 9.8 6.0 9.8 0.2 9.8 9.8 9.8 in (a) (%) Neutralization ratioof 0 100 0 0 100 0 100 0 0 0 carboxyl group in (a) (%) Δsp of resin (a)and resin 0.4 0.3 0.7 0.8 0.7 0.6 0.5 0.5 0.5 1.1 (b) Weight averagemolecular 6 4 270 6 4 6 4 320 320 270 weight of (a) (×1000) In theinside of ◯ ◯ X ◯ ◯ ◯ ◯ X X X quadrangular area ABCD Volume averageparticle 0.09 0.05 0.05 0.09 0.05 0.09 0.05 0.10 0.10 0.05 diameter of(A) (μm) Volume average particle 5.4 5.2 5.6 5.6 5.4 5.2 5.6 5.6 5.6 5.3diameter of (C) (μm) Surface coverage (%) 0 0 90 0 0 0 0 100 100 80Volume average particle 1.17 1.18 1.15 1.17 1.17 1.14 1.16 1.21 1.211.13 diameter/number average particle diameter of (C) Average degree of0.98 0.98 0.98 0.98 0.98 0.98 0.98 0.97 0.97 0.96 circularity of (C)Smoothness of particle X X X X X X X X Δ X surface of (C) Electrostaticcharge 2 −2 −8 −2 −3 −2 −3 −17 −17 −12 (μC/g) Low temperature fixing 105105 135 105 105 125 125 140 140 125 property (° C.) Thermal resistant XX ◯ X X X X ◯ ◯ ◯ storage stability

The measurement of the average degree of circularity was carried outaccording to the above-mentioned manner.

The measurement methods for the electrostatic property, thermalresistant storage stability, low temperature fixing property, andsurface smoothness are as follows.

[Electrostatic Property] (Electrostatic Charge)

Resin particle 0.5 g and iron powder (F-150, manufactured by Nippon IronPowder Corporation Ltd.) 10 g were precisely weighed and put in a 50 ccground stopper glass bottle and plugged and set in a tumbler shakermixer (manufactured by Willy Bachofen) at 23° C. and 50% RH and rotatedat 90 rpm for 2 minutes. After the stirring, 0.2 g of the mixed powderwas packed in a blow-off powder charge quantity measurement apparatus(TB-203, manufactured by KYOCERA CORP) in which a stainless net with 20μm meshes was installed and the charge quantity of the remaining ironpowder in blow pressure 10 KPa and suction pressure 5 KPa and the chargequantity of the resin particles was calculated according to thestandardized method. As the minus charge quantity is higher, theelectrostatic property is more excellent for a toner.

[Thermal Resistant Storage Stability]

The resin particles were kept still for 15 hours in a dryer controlledto be at 50° C. and evaluation was carried out in accordance with theblocking extent based on the following standard.

◯: no blocking occurred;

Δ: although blocking occurred, particles were easily dispersed byapplying power; and

x: blocking occurred and even if power was applied, particles were notdispersed.

[Low Temperature Fixing Property]

Aerosil R972 (manufactured by Nippon Aerosil) in an amount of 1.0% wasadded to the resin particles and well and evenly mixed and the obtainedpowder was spread on paper in a weight density of 0.6 mg/cm² (in thiscase a printer from which a heat fixing unit was disassembled was usedfor the method for spreading the powder on the paper (if it is possibleto evenly spread the powder with the above-mentioned weight density, anyother method may be employed.)). The paper was passed through a pressureroller in conditions of a fixing speed (heating roller peripheral speed)of 213 mm/sec and a fixing pressure (pressure roller pressure) 10 kg/cm²and the temperature of occurrence of cold off-set was measured.

[Surface Smoothness]

The surfaces of the resin particles (C) were photographed at 10,000 and30,000 magnification by a scanning electron microscope (SEM) andevaluated accordingly.

⊚: no unevenness in the surface and very smooth:

◯: although uneven portion is observed in the surface; comprehensivelyunevenness is scarce and the surface is smooth:

Δ: although the entire surface is uneven, no granular substance derivedfrom the resin (a) is observed: and

x: the entire surface is very rough, or granules derived from the resin(a) are observed.

INDUSTRIAL APPLICABILITY

Since resin dispersions and resin particles of the inventions have evenparticle diameters and excellent in electrostatic property and thermalresistant storage stability, they are very useful for resin particles tobe used for resins for slush molding, powder coating, spacers forelectronic parts such as liquid crystals, standard particles forelectronic measurement instruments, toners for electrophotograph,electrostatic recording, and electrostatic printing, various kinds ofhot melt adhesives, and other molding materials.

The invention claimed is:
 1. Core-shell type resin particles (C2) eachcomprising a film shell layer (P) in one or more layer structure made ofa first resin (a) and a core layer (Q) in one layer structure made of asecond resin (b), wherein the weight ratio of the film shell layer (P)and the core layer (Q) is in a range of (0.1:99.9) to (70:30), thecontent of volatile components of the resin particles (C2) is 2% byweight or lower, and the resin (a) has an initial softening temperatureof 40 to 270° C., a glass transition temperature of 20 to 100° C., aflow temperature 60 to 220° C., and the difference of the glasstransition temperature and the flow temperature in a range of 0 to 120°C.
 2. The resin particles according to claim 1, wherein the resin (a) isat least one resin selected from polyester resins, epoxy resins, andvinyl resins.
 3. The resin particles according to claim 1, wherein theresin (b) is at least one resin selected from polyester resins,polyurethane resins, epoxy resins, and vinyl resins.
 4. The resinparticles according to claim 1, wherein the resin particles (C2) areobtained by a process comprising the steps of: dispersing the resin (b)or its solvent solution, alternatively a precursor (b0) of the resin (b)or its solvent solution, further causing a reaction of the precursor(b0) in the case of using the precursor (b0) or its solvent solution, ina water-based dispersion of resin particles (A) comprising the resin(a); obtaining a water-based dispersion (X1) of the resin particles (C1)each comprising resin particles (B) bearing the resin particles (A) byforming the resin particles (B) comprising the resin (b) in thewater-based dispersion of the resin particles (A); obtaining awater-based dispersion (X2) of resin particles (C21) formed by forming ashell layer (P) in the form of a film made of the resin particles (A) bymaking the resin particles (A) into a film on the surface of a corelayer (Q) containing the resin particles (B) in the water-baseddispersion (X1); and finally removing the water-based solvent from thewater-based dispersion (X2).
 5. The resin particles according to claim4, wherein, in the step of obtaining a water-based dispersion (X2) ofresin particles (C21) formed by forming a shell layer (P) in the form ofa film made of the resin particles (A) by making the resin particles (A)into a film on the surface of a core layer (Q) containing the resinparticles (B) in the water-based dispersion (X1), the shell layer (P) isformed in the form of a film made of the resin particles (A) on thesurface of the core layer (Q) containing the resin particles (B) bydissolving in the solvent the resin particles (A) adhering to (B) and/ormelting the resin particles (A) adhering to (B) in the water-baseddispersion (X1).
 6. A resin for slush molding, powder coating, spacersfor electronic part production, standard particles for electronicmeasurement instruments, electrophotograph toners, electrostaticrecording toners, electrostatic printing toners or hot melt adhesives,the resin comprising the resin particles according to claim 1.